Bibliography

  • Stefan Schlechtweg's NPR bib list
  • ACM's Searchable Bibliography Index


    The following is also available as a bib file (containing most citations up to and including 2001): npr.bib.

    Some NPR-related Publications in BibTex format

    
    @article{Raskar:2001:HSN,
             author = {Ramesh Raskar },
             title = {Hardware Support for Non-photorealistic Rendering },
             journal = {2001 SIGGRAPH / Eurographics Workshop on Graphics Hardware},
             year = {2001},
             month = {August},
             editor = { },
             publisher = {ACM Press},
             pages = { },
             note = { },
             annote = {  },
          }
    
    @article{Freudenberg:2001:WIF,
             author = {Bert Freudenberg and Maic Masuch and Thomas Strothotte},
             title = {Walk-Through Illustrations: Frame-Coherent Pen-and-Ink Style in a Game Engine},
             volume = {20},
             number = {3},
             journal = {Computer Graphics Forum},
             year = {2001},
             publisher = {Blackwell Publishers},
             note = {ISSN 1067-7055},
             annote = { In this paper we show how a game engine designed to generate
    photorealistic images can be extended to produce non-photorealistic
    and hybrid renditions. We introduce new hardware-based methods to
    accomplish pen-and-ink illustrations. The combination of the highly
    optimized processing of a game engine and the use of hardware for NPR
    algorithms yields real-time animation of pen-and-ink illustrations.
    The particular advance of this method is that it yields the first
    real-time, frame-coherent pen-and-ink animations which maintain both
    tone and texture. }, }
    
    
          @article{Bourguignon:2001:DFI,
             author = {David Bourguignon and Marie-Paule Cani and George Drettakis},
             title = {Drawing for Illustration and Annotation in 3D},
             volume = {20},
             number = {3},
             journal = {Computer Graphics Forum},
             year = {2001},
             publisher = {Blackwell Publishers},
             note = {ISSN 1067-7055},
             keywords = {drawing, stroke-based illustration, interface},
             annote = { We present a system for sketching in 3D, which
          strives to preserve the degree of expression, imagination, and
          simplicity of use achieved by 2D drawing. Our system directly
          uses user-drawn strokes to infer the sketches representing the
          same scene from different viewpoints, rather than attempting to
          reconstruct a 3D model.  This is achieved by interpreting
          strokes as indications of a local surface silhouette or
          contour. Strokes thus deform and disappear progressively as we
          move away from the original viewpoint. They may be occluded by
          objects indicated by other strokes, or, in contrast, be drawn
          above such objects. The user draws on a plane which can be
          positioned explicitly or relative to other objects or strokes in
          the sketch. Our system is interactive, since we use fast
          algorithms and graphics hardware for rendering. We present
          applications to education, design, architecture and fashion,
          where 3D sketches can be used alone or as an annotation of an
          existing 3D model. }, }
    
    
    
    @article{Kang:2001:TIT,
             author = {Hyung Woo Kang and Soon Hyoung Pyo and Ken-ichi Anjyo and Sung Yong Shin},
             title = {Tour Into the Picture using a Vanishing Line and its Extension to  Panoramic Images},
             volume = {20},
             number = {3},
             journal = {Computer Graphics Forum},
             year = {2001},
             publisher = {Blackwell Publishers},
             note = {ISSN 1067-7055},
             keywords = {Image-based modeling/rendering, projective geometry, vanishing line,  panoramic image},
             annote = { Tour into the picture (TIP) proposed by Horry et
          al.is a method for generating a sequence of walk-through images
          from a single reference picture (or image). By navigating a 3D
          scene model constructed from the picture, TIP produces
          convincing 3D effects. Assuming that the picture has one
          vanishing point, they proposed the scene modeling scheme called
          spidery mesh. However, this scheme has to go through major
          modification when the picture contains multiple vanishing points
          or does not have any well-defined vanishing point. Moreover, the
          spidery mesh is hard to generalize for other types of images
          such as panoramic images. In this paper, we propose a new scheme
          for TIP which is based on a single vanishing line instead of a
          vanishing point. Based on projective geometry, our scheme is
          simple and yet general enough to address the problems faced with
          the previous method. We also show that our scheme can be
          naturally extended to a panoramic image. }, }
    
    
    @article{Way:2001:TSO,
             author = {Der-Lor Way and Zen-Chung Shih},
             title = {The Synthesis of Rock Textures in Chinese Landscape Painting},
             volume = {20},
             number = {3},
             journal = {Computer Graphics Forum},
             year = {2001},
             publisher = {Blackwell Publishers},
             note = {ISSN 1067-7055},
       annote = {In Chinese landscape painting, rock textures portray the
          orientation of mountains and contribute to the atmosphere. Many
          landscape-painting skills are required according to the type of
          rock. Landscape painting is the major theme of Chinese
          painting. Over the centuries, masters of Chinese landscape
          painting developed various texture strokes. Hemp-fiber and
          axe-cut are two major types of texture strokes. A slightly
          sinuous and seemingly broken line, the hemp-fiber stroke is used
          for describing the gentle slopes of rock formations whereas the
          axe-cut stroke best depicts hard, rocky surfaces. This paper
          presents a novel method of synthesizing rock textures in Chinese
          landscape painting, useful not only to artists who want to paint
          interactively, but also in automated rendering of natural
          scenes.  The method proposed underwrites the complete painting
          process after users have specified only the contour and
          parameters. }, }
    
    
    
    @article{Durand:2001:DSH,
             author = {Fredo Durand and Victor Ostromoukhov and Mathieu Miller and Francois Duranleau  and Julie Dorsey},
             title = { Decoupling Strokes and High-Level Attributes for Interactive Traditional Drawing},
             journal = {Eurographics Workshop on Rendering},
             year = {2001},
             publisher = {Springer-Verlag},
             pages = {},
             note = {},
             annote = {},
          }
    
    @article{Gooch:2001:ACI,
             author = {Bruce Gooch and Eric Reinhard and Chris Moulding and Peter Shirley },
             title = { Artistic Composition for Image Creation },
             journal = {Eurographics Workshop on Rendering},
             year = {2001},
             publisher = {Springer-Verlag},
             pages = {},
             note = {},
             annote = {},
          }
    
    
    @article{Visvalingam:2001:TCE,
             author = {M Visvalingam and K Dowson},
             title = {Towards Cognitive Evaluation of Computer-drawn Sketches},
             volume = {17},
             number = {4},
             journal = {The Visual Computer},
             year = {2001},
             month = {},
             pages = {},
             keywords = {},
             annote = {  },
          }
    
    @article{Cornish:2001:VPF,
             author = {Derek Cornish and Andrea Rowan and David Luebke},
             title = {View-Dependent Particles for Interactive Non-Photorealistic Rendering},
             journal = {Graphics Interface 2001},
             year = {2001},
             month = {June},
             editor = {Benjamin Watson and John W. Buchanan},
             pages = {151--158},
             note = {ISBN 0-96888-080-0}, 
       annote = {We present a novel framework for non-photorealistic
          rendering (NPR) based on view-dependent geometric simplification
          techniques. Following a common thread in NPR research, we
          represent the model as a system of particles, which will be
          rendered as strokes in the final image and which may optionally
          overlay a polygonal surface. Our primary contribution is the use
          of a hierarchical view-dependent clustering algorithm to
          regulate the number and placement of these particles. This
          algorithm unifies several tasks common in artistic rendering,
          such as placing strokes, regulating the screen-space density of
          strokes, and ensuring inter-frame coherence in animated or
          interactive rendering. View-dependent callback functions
          determine which particles are rendered and how to render the
          associated strokes. The resulting framework is interactive and
          extremely flexible, letting users easily produce and experiment
          with many different art-based rendering styles.  }, }
    
    @article{Sloan:2001:TLS,
             author = {Peter-Pike Sloan and William Martin and Amy Gooch and Bruce Gooch},
             title = {The Lit Sphere: A Model for Capturing NPR Shading from Art},
             journal = {Graphics Interface 2001},
             year = {2001},
             month = {June},
             editor = {Benjamin Watson and John W. Buchanan},
             pages = {143--150},
             note = {ISBN 0-96888-080-0},
             annote = {While traditional graphics techniques provide for
          the realistic display of three-dimensional objects, these
          methods often lack the flexibility to emulate expressive effects
          found in the works of artists such as Michelangelo and Cezanne.
          We introduce a technique for capturing custom artistic shading
          models from sampled art work. Our goal is to allow users to
          easily generate shading models which give the impression of
          light, depth, and material properties as accomplished by
          artists.  Our system provides real-time feedback to immediately
          illustrate aesthetic choices in shading model design, and to
          assist the user in the exploration of novel viewpoints. We
          describe rendering algorithms which are easily incorporated into
          existing shaders, making non-photorealistic rendering of
          materials such as skin, metal, or even painted objects fast and
          simple. The flexibility of these methods for generating shading
          models enables users to portray a large range of materials as
          well as to capture the look and feel of a work of art. (Color
          images can be found at
          http://www.cs.utah.edu/npr/papers/LitSphere_HTML.) }, }
    
    @article{Agrawala:2001:RER,
             author = {Maneesh Agrawala and Chris Stolte},
             title = {Rendering Effective Route Maps: Improving Usability Through
          Generalization},
             journal = {Proceedings of SIGGRAPH 2001},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {2001},
             month = {August},
             editor = {Eugene Fiume},
             publisher = {ACM Press / ACM SIGGRAPH},
             pages = {241--250},
             note = {ISBN 1-58113-292-1},
             keywords = {Information Visualization, Non-Realistic Rendering, WWW Applications,  Human Factors},
             annote = {Route maps, which depict a path from one location
          to another, have emerged as one of the most popular applications
          on the Web. Current computer-generated route maps, however, are
          often very difficult to use. In this paper we present a set of
          cartographic generalization techniques specifically designed to
          improve the usability of route maps. Our generalization
          techniques are based both on cognitive psychology research
          studying how route maps are used and on an analysis of the
          generalizations commonly found in handdrawn route maps. We
          describe algorithmic implementations of these generalization
          techniques within LineDrive, a real-time system for
          automatically designing and rendering route maps.  Feedback from
          over 2200 users indicates that almost all believe LineDrive maps
          are preferable to using standard computer-generated route maps
          alone. }, }
    
    
    
    
    @article{Agrawala:1995:3PO,
             author = {Maneesh Agrawala and Andrew C. Beers and Marc Levoy},
             title = {3D Painting on Scanned Surfaces },
             journal = {1995 Symposium on Interactive 3D Graphics},
             year = {1995},
             month = {April},
             editor = {Pat Hanrahan and Jim Winget},
             publisher = {ACM SIGGRAPH},
             pages = {145--150},
             note = {ISBN 0-89791-736-7},
          }
                                                                                                
      
     #2:
          @article{Agrawala:2000:AMR,
             author = {Maneesh Agrawala and Denis Zorin and Tamara Munzner },
             title = {Artistic Multiprojection Rendering},
             journal = {Rendering Techniques 2000: 11th Eurographics Workshop on Rendering},
             year = {2000},
             month = {June},
             editor = {Bernard P{\'{e}}roche and Holly Rushmeier},
             publisher = {Eurographics},
             pages = {125--136},
             note = {ISBN 3-211-83535-0},
             annote = {In composing hand-drawn images of 3D scenes,
          artists often alter the projection for each object in the scene
          independently, thereby generating multiprojection images. We
          present an interactive tool for creating such multiprojection
          images and animations, consisting of two parts: a
          multiprojection rendering algorithm and an interactive interface
          for attaching local cameras to the scene geometry. We describe a
          new set of techniques for resolving visibility between geometry
          rendered with different local cameras. We also develop several
          camera constraints that are useful when initially setting local
          camera parameters and when animating the scene. We demonstrate
          applications of our methods for generating a variety of artistic
          effects in still images and in animations. }, }
    
    
          @article{Hertzmann:2001:IA,
             author = {Aaron Hertzmann and Charles E. Jacobs and Nuria Oliver and Brian
          Curless and David H. Salesin},
             title = {Image Analogies},
             journal = {Proceedings of SIGGRAPH 2001},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {2001},
             month = {August},
             editor = {Eugene Fiume},
             publisher = {ACM Press / ACM SIGGRAPH},
             pages = {327--340},
             note = {ISBN 1-58113-292-1},
             keywords = {example-based rendering, texture synthesis,
             non-photorealistic rendering, Markov random fields,
             autoregression, texture-by-numbers, texture transfer},
             annote = {This paper describes a new framework for processing
          images by example, called "image analogies." The framework
          involves two stages: a design phase, in which a pair of images,
          with one image purported to be a "filtered" version of the
          other, is presented as "training data"; and an application
          phase, in which the learned filter is applied to some new target
          image in order to create an "analogous" filtered result. Image
          analogies are based on a simple multi-scale autoregression,
          inspired primarily by recent results in texture synthesis. By
          choosing different types of source image pairs as input, the
          framework supports a wide variety of "image filter" effects,
          including traditional image filters, such as blurring or
          embossing; improved texture synthesis, in which some textures
          are synthesized with higher quality than by previous approaches;
          super-resolution, in which a higher-resolution image is inferred
          from a low-resolution source; texture transfer, in which images
          are "texturized" with some arbitrary source texture; artistic
          filters, in which various drawing and painting styles are
          synthesized based on scanned real-world examples; and
          texture-by-numbers, in which realistic scenes, composed of a
          variety of textures, are created using a simple painting
          interface. }, }
    
    @article{Baxter:2001:DIH,
             author = {Bill Baxter and Vincent Scheib and Ming C. Lin and Dinesh Manocha},
             title = {DAB: Interactive Haptic Painting With 3D Virtual Brushes},
             journal = {Proceedings of SIGGRAPH 2001},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {2001},
             month = {August},
             editor = {Eugene Fiume},
             publisher = {ACM Press / ACM SIGGRAPH},
             pages = {461--468},
             note = {ISBN 1-58113-292-1},
             keywords = {Haptics, Human Computer Interaction, Painting Systems, Deformable Brush Model},
             annote = {We present a novel painting system with an
          intuitive haptic interface, which serves as an expressive
          vehicle for inter-ctively creating painterly works. We introduce
          a deformable, 3D brush model, which gives the user natural
          control of complex brush strokes. The force feedback enhances
          the sense of realism and provides tactile cues that enable the
          user to better manipulate the paint brush. We have also
          developed a bidirectional, two-layer paint model that, combined
          with a palette interface, enables easy loading of complex blends
          onto our 3D virtual brushes to generate interesting paint
          effects on the canvas. The resulting system, DAB, provides the
          user with an artistic setting, which is conceptually equivalent
          to a real-world painting environment. Several users have tested
          DAB and were able to start creating original art work within
          minutes. }, }
    
    @article{Hausner:2001:SDM,
             author = {Alejo Hausner},
             title = {Simulating Decorative Mosaics},
             journal = {Proceedings of SIGGRAPH 2001},
             year = {2001},
             month = {August},
             editor = {Eugene Fiume},
             publisher = {ACM Press / ACM SIGGRAPH},
             pages = {573--578},
             note = {ISBN 1-58113-292-1},
             annote = {This paper presents a method for simulating
          decorative tile mosaics.  Such mosaics are challenging because
          the square tiles that comprise them must be packed tightly and
          yet must follow orientations chosen by the artist. Based on an
          existing image and user-selected edge features, the method can
          both reproduce the image's colours and emphasize the selected
          edges by placing tiles that follow the edges. The method uses
          centroidal voronoi diagrams which normally arrange points in
          regular hexagonal grids. By measuring distances with an
          manhattan metric whose main axis is adjusted locally to follow
          the chosen direction field, the centroidal diagram can be
          adapted to place tiles in curving square grids
          instead. Computing the centroidal voronoi diagram is made
          possible by leveraging the z-buffer algorithm available in many
          graphics cards. }, }
    
    @article{Praun:2001:RH,
             author = {Emil Praun and Hugues Hoppe and Matthew Webb and Adam Finkelstein },
             title = {Real-Time Hatching},
             journal = {Proceedings of SIGGRAPH 2001},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {2001},
             month = {August},
             editor = {Eugene Fiume},
             publisher = {ACM Press / ACM SIGGRAPH},
             pages = {579--584},
             note = {ISBN 1-58113-292-1},
             keywords = {non-photorealistic rendering, line art, multitexturing,
          chicken-and-egg problem },
             annote = {Drawing surfaces using hatching strokes
          simultaneously conveys material, tone, and form. We present a
          real-time system for non-photorealistic rendering of hatching
          strokes over arbitrary surfaces. During an automatic preprocess,
          we construct a sequence of mip-mapped hatch images corresponding
          to different tones, collectively called a tonal art map. Strokes
          within the hatch images are scaled to attain appropriate stroke
          size and density at all resolutions, and are organized to
          maintain coherence across scales and tones. At runtime, hardware
          multitexturing blends the hatch images over the rendered faces
          to locally vary tone while maintaining both spatial and temporal
          coherence. To render strokes over arbitrary surfaces, we build a
          lapped texture parametrization where the overlapping patches
          align to a curvature-based direction field. We demonstrate
          hatching strokes over complex surfaces in a variety of
          styles. }, }
    
    
    @article{Sourin:2001:FBV,
             author = {Alexei Sourin},
             title = {Functionally Based Virtual Computer Art},
             journal = {2001 ACM Symposium on Interactive 3D Graphics},
             year = {2001},
             month = {March},
             editor = {John F. Hughes and Carlo H. S{\'{e}}quin},
             pages = {77--84},
             note = {ISBN 1-58113-292-1},
             keywords = {Computer art, embossing, carving, virtual reality, functionally based
          shape modeling},
             annote = {This article describes how virtual embossing and
          wood cutting can be done using the function representation of a
          shape and tools. The software is implemented as an interactive
          shape modeler where a functional model of the shape is
          subsequently modified with offset and set-theoretic
          operations. For visualization, interactive ray tracing is
          used. Bounding boxes together with the spatial organization of
          the functional model provide the required fast function
          evaluation that is usually a bottleneck for functionally based
          shape modeling systems. The software runs on a personal
          computer. }, }
                                                                                                
      @article{Keefe:2001:CAF,
             author = {Daniel F. Keefe and Daniel Acevedo Feliz and Tomer Moscovich and David
          H. Laidlaw and Joseph J. LaViola Jr.},
             title = {CavePainting: A Fully Immersive 3D Artistic Medium and Interactive Experience},
             journal = {2001 ACM Symposium on Interactive 3D Graphics},
             year = {2001},
             month = {March},
             editor = {John F. Hughes and Carlo H. S{\'{e}}quin},
             pages = {85--94},
             note = {ISBN 1-58113-292-1},
             keywords = {3D painting, 3D modeling, gestures, tangible user interface, Cave},
             annote = {CavePainting is an artistic medium that uses a 3D
          analog of 2D brush strokes to create 3D works of art in a fully
          immersive Cave environment. Physical props and gestures are used
          to provide an intuitive interface for artists who may not be
          familiar with virtual reality. The system is designed to take
          advantage of the 8 ft. × 8 ft. × 8 ft. space in which the artist
          works. CavePainting enables the artist to create a new type of
          art and provides a novel approach to viewing this art after it
          has been created. In this paper, we describe Cave-Painting s 3D
          brush strokes, color pickers, artwork viewing mode, and
          interface. We also present several works of art created using
          the system along with feedback from artists. Artists are excited
          about this form of art and the gestural, full-body experience of
          creating it. }, }
                                                                                                
      @article{Yen:2001:ESC,
             author = {Jane Yen and Carlo S{\'{e}}quin},
             title = {Escher Sphere Construction Kit},
             journal = {2001 ACM Symposium on Interactive 3D Graphics},
             year = {2001},
             month = {March},
             editor = {John F. Hughes and Carlo H. S{\'{e}}quin},
             pages = {95--98},
             note = {ISBN 1-58113-292-1},
             keywords = {M. C. Escher, solid modeling, tessellation, spherical symmetry, spherical tiling, tile editor},
             annote = {M. C. Escher created a myriad of amazing planar
          tessellations, yet only a few three-dimensional ones such as his
          wooden fish ball and dodecahedral flower.  We have developed an
          interactive program to design and manufacture "Escher Spheres" -
          sets of tiles that can be assembled into spherical balls. The
          user chooses from a set of predefined symmetry groups and then
          deforms the boundaries of the basic domain tile; all
          corresponding points based on the chosen symmetry class move
          concurrently, instantly showing the overall result. The interior
          of the tile can be embellished with a bas-relief. Finally the
          tile is radially extruded and output as a solid model suitable
          for free-form fabrication. }, }
    
    @article{Kowalski:2001:UCE,
             author = {Michael A. Kowalski and John F. Hughes and Cynthia Beth Rubin and Jun
          Ohya},
             title = {User-Guided Composition Effects For Art-Based Rendering },
             journal = {2001 ACM Symposium on Interactive 3D Graphics},
             year = {2001},
             month = {March},
             editor = {John F. Hughes and Carlo H. S{\'{e}}quin},
             pages = {99--102},
             note = {ISBN 1-58113-292-1},
          }
    
    @article{Mohr:2001:NIS,
             author = {Alex Mohr and Michael Gleicher},
             title = {Non-Invasive, Interactive, Stylized Rendering},
             journal = {2001 ACM Symposium on Interactive 3D Graphics},
             year = {2001},
             month = {March},
             editor = {John F. Hughes and Carlo H. S{\'{e}}quin},
             pages = {175--178},
             note = {ISBN 1-58113-292-1},
             keywords = {Non-photorealistic rendering, Real-time, Stylized, Interactive, 3D},
             annote = {In this paper, we show how many interactive 3D
          applications visual styles can be changed to new, different, and
          interesting visual styles non-invasively. Our method lets a
          single stylized renderer be used with many applications. We
          implement this by intercepting the OpenGL graphics library and
          changing the drawing calls. Even though OpenGL only receives
          low-level information from an application, computation on this
          data and assumptions about the application can give us enough
          information to develop stylized renderers. }, }
    
    
    
    @article{Igarashi:2001:AUF,
             author = {Takeo Igarashi and Dennis Cosgrove},
             title = {Adaptive Unwrapping for Interactive Texture Painting},
             journal = {2001 ACM Symposium on Interactive 3D Graphics},
             year = {2001},
             month = {March},
             editor = {John F. Hughes and Carlo H. S{\'{e}}quin},
             pages = {209--216},
             note = {ISBN 1-58113-292-1},
             keywords = {texture mapping, texture painting, interactive 3D graphics,
          multiresolution paint, zooming, 3D content creation},
        annote = {We present a method for dynamically generating an
          efficient texture bitmap and its associated UV-mapping in an
          interactive texture painting system for 3D models. Typical 3D
          texture painting programs require the user to explicitly define
          the underlying UV-mapping from 3D geometry to 2D bitmap prior to
          painting.  This mapping is unchanged by the painting
          process. However, a predefined UV-mapping can cause distortion
          at arbitrary locations and waste bitmap memory in unpainted
          areas. To solve these problems, we propose an adaptive
          unwrapping mechanism where the system dynamically creates a
          tailored UV-mapping for newly painted polygons during the
          interactive painting process. This eliminates the distortion of
          brush strokes, and the resulting texture bitmap is more compact
          because the system allocates texture space only for the painted
          polygons. In addition, this dynamic texture allocation allows
          the user to paint smoothly at any zoom level. This technique can
          be efficiently implemented using standard 3D rendering engines,
          and the painted models can be stored as standard textured
          polygonal models. We implemented a prototype system, called
          Chameleon, and our users experiences suggest that our technique
          is very useful for simple painting by casual users. }, }
                                                                                    
          @article{Tolba:2001:APD,
             author = {Osama Tolba and Julie Dorsey and Leonard McMillan},
             title = {A Projective Drawing System},
             journal = {2001 ACM Symposium on Interactive 3D Graphics},
             year = {2001},
             month = {March},
             editor = {John F. Hughes and Carlo H. S{\'{e}}quin},
             pages = {25--34},
             note = {ISBN 1-58113-292-1},
             keywords = {Image-based Modeling and Rendering, Misc. 2D graphics, Non-Euclidean Spaces, Non-Photorealistic Rendering},
           annote = {We present a novel drawing system for composing and
          rendering perspective scenes. Our approach uses a projective 2D
          representation for primitives rather than a conventional 3D
          description. This allows drawings to be composed with the same
          ease as traditional illustrations, while providing many of the
          advantages of a 3D model. We describe a range of user-interface
          tools and interaction techniques that give our system its
          3D-like capabilities. We provide vanishing point guides and
          perspective grids to aid in drawing free-hand strokes and
          composing perspective scenes. Our system also has tools for
          intuitive navigation of a virtual camera, as well as methods for
          manipulating drawn primitives so that they appear to undergo 3D
          translations and rotations. We also support automatic shading of
          primitives using either realistic or non-photorealistic
          styles. Our system supports drawing and shading of extrusion
          surfaces with automatic hidden surface removal and highlighted
          silhouettes. Casting shadows from an infinite light source is
          also possible with minimal user intervention. }, }
                                                                                                
                  
      
    
    @inproceedings{Buchanan:2000:NPAR,
      author = {John W. Buchanan and Mario C. Sousa},
      title =  {The edge buffer: A data structure for easy silhouette rendering},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    @inproceedings{Buck:2000:NPAR,
      author = {Ian Buck and Adam Finkelstein and Charles Jacobs and 
                Allison Klein and David H. Salesin and Jashua Seims and 
                Richard Szeliski and Kentaro Toyama},
      title =  { Performance-Driven Hand-Drawn Animation},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    @inproceedings{Cohen:2000:NPAR,
      author = {Jonathan M. Cohen and John F. Hughes and Robert C. Zeleznik},
      title =  { Harold: A World Made of Drawings},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    @article{Deussen:2000,
      author = {Oliver Deussen and Thomas Strothotte},
      title = {Computer-Generated Pen-and-Ink Illustration of Trees},
      journal = {Proceedings of SIGGRAPH 2000},
      series = {Computer Graphics Proceedings, Annual Conference Series},
      year = {2000},
      month = {July},
      editor = {Kurt Akeley},
      publisher = {ACM Press / ACM SIGGRAPH / Addison Wesley Longman},
      pages = {13--18},
      note = {ISBN 1-58113-208-5},
      keywords = {Biological Systems, Frame Buffer Tricks, Non-Realistic Rendering},
      annote = {We present a method for automatically rendering
                pen-and-ink illustrations of trees. A given 3-d tree model
                is illustrated by the tree skeleton and a visual
                representation of the foliage using abstract drawing
                primitives. Depth discontinuities are used to determine
                what parts of the primitives are to be drawn; a hybrid
                pixel-based and analytical algorithm allows us to deal
                efficiently with the complex geometric data. Using the
                proposed method we are able to generate illustrations with
                different drawing styles and levels of abstraction. The
                illustrations generated are spatial coherent, enabling us
                to create animations of sketched
                environments. Applications of our results are found in
                architecture, animation and landscaping. }, 
    }
    
    
    @inproceedings{Girshick:2000:NPAR,
      author = {Ahna Girshick and Victoria Interrante and Steven Haker and 
                Todd Lemoine},
      title =  {Line Direction Matters: An Argument for the Use of Principal
                Directions in 3D Line Drawings },
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    @inproceedings{Hertzmann:2000:NPAR,
      author = {Aaron Hertzmann and Ken Perlin},
      title =  { Painterly Rendering for Video and Interaction},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    
    @article{Kaplan:2000:E,
      author = {Craig S. Kaplan and David H. Salesin},
      title = {Escherization},
      journal = {Proceedings of SIGGRAPH 2000},
      series = {Computer Graphics Proceedings, Annual Conference Series},
      year = {2000},
      month = {July},
      editor = {Kurt Akeley},
      publisher = {ACM Press / ACM SIGGRAPH / Addison Wesley Longman},
      pages = {499--510},
      note = {ISBN 1-58113-208-5},
      keywords = {Tilings, tesselations, morphing, optimization, simulated
                  annealing, Escher},
      annote = {This paper introduces and presents a solution to the '
                Escherization' problem: given a closed figure in the
                plane, find a new closed figure that is similar to the
                original and tiles the plane. Our solution works by using
                a simulated annealer to optimize over a parameterization
                of the "isohedral" tilings, a class of tilings that is
                flexible enough to encompass nearly all of Escher's own
                tilings, and yet simple enough to be encoded and explored
                by a computer. We also describe a representation for
                isohedral tilings that allows for highly interactive
                viewing and rendering. We demonstrate the use of these
                tools - along with several additional techniques for
                adding decorations to tilings - with a variety of original
                ornamental designs. }, 
    }
    
    @inproceedings{Kaplan:2000:NPAR,
      author = {Matthew Kaplan and Bruce Gooch and Elaine Cohen  },
      title =  {Interactive Artistic Rendering },
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    @inproceedings{Lake:2000:NPAR,
      author = {Adam Lake and Carl Marshall and Mark Harris and Marc Blackstein},
      title =  { Stylized Rendering Techniques for Scalable Real-Time 3D Animation},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    @inproceedings{Markosian:2000:NPAR,
      author = {Lee Markosian and Barbara J. Meier and Michael A. Kowalski and Loring S. Holden and J.D. Northrup and John F. Hughes},
      title =  { Art-based Rendering with Continuous Levels of Detail},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    @inproceedings{Martin:2000:NPAR,
      author = {D. Martin and S. Garcia and J. C. Torres},
      title =  { Observer dependent deformations in illustration},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    
    @article{Mestetskii:2000:FCA,
       author = {L.M. Mestetskii},
       title = {Fat curves and representation of planar figures},
       volume = {24},
       number = {1},
       journal = {Computers \& Graphics},
       year = {February 2000},
       publisher = {Pergamon Press / Elsevier Science},
       pages = {9--21},
       note = {ISSN 0097-8493},
       keywords = {Fat curve; B{\'{e}}zier curve; Implicit representation; Engraving},
       annote = {A fat curve is a "curve having a width;" it is the trace
                 left by a moving circle of variable radius. A union of a
                 finite number of fat curves is called engraving. This
                 paper describes mathematical representation of fat
                 curves, their rendering on standard (raster) display
                 devices, proposes a B{\'{e}}zier representation for fat
                 curves and discusses 2D modelling through engraving. A
                 method for the approximation of arbitrary bitmap binary
                 images by engraving is also presented. }, 
    }
    
    
    @inproceedings{Northrup:2000:NPAR,
      author = {J.D. Northrup and Lee Markosian},
      title =  { Artistic Silhouettes: A Hybrid Approach},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    @inproceedings{Noot:2000:NPAR,
      author = {Han Noot and Zsofia Ruttkay},
      title =  { Animated CharToon Faces},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
     
    @inproceedings{Snibbe:2000:NPAR,
      author = {Scott Sona Snibbe and Golan Levin},
      title =  { Interactive Dynamic Abstraction},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="",
    }
    
     @article{Sousa:2000:OMO,
      author = {Mario Costa Sousa and John W. Buchanan},
      title = {Observational Models of Graphite Pencil Materials},
      volume = {19},
      number = {1},
      journal = {Computer Graphics Forum},
      year = {2000},
      month = {March},
      publisher = {Blackwell Publishers},
      pages = {27--49},
      note = {ISSN 1067-7055},
      annote = {This paper presents models for graphite pencil,
                drawing paper, blenders, and kneaded eraser that
                produce realistic looking pencil marks,
                textures, and tones. Our models are based on an
                observation of how lead pencils interact with
                drawing paper, and on the absorptive and
                dispersive properties of blenders and erasers
                interacting with lead material deposited over
                drawing paper. The models consider parameters
                such as the particle composition of the lead,
                the texture of the paper, the position and shape
                of the pencil materials, and the pressure
                applied to them. We demonstrate the capabilities
                of our approach with a variety of images and
                compare them to digitized pencil drawings. We
                also present image-based rendering results
                implementing traditional graphite pencil tone
                rendering methods. }, 
    }
    
    
    @article{Deussen:2000:SIG,
             author = {Oliver Deussen and Thomas Strothotte},
             title = {Pen-and-Ink Illustration of Trees},
             journal = {Proceedings of SIGGRAPH 2000},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {July 2000},
             editor = {},
             publisher = {ACM SIGGRAPH},
             pages = {},
             note = {Held in New Orleans, Louisianna.},
             keywords = {},
             annote = {  },
          }
    
    @article{Klein:2000:SIG,
             author = {Allison W. Klein and Wilmot Li and Misha Kazhdan and 
                       Wagner Toledo Corrêa and Adam Finkelstein and Thomas Funkhouser },
             title = {Non-Photorealistic Virtual Environments },
             journal = {Proceedings of SIGGRAPH 2000},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {July 2000},
             editor = {},
             publisher = {ACM SIGGRAPH},
             pages = {},
             note = {Held in New Orleans, Louisianna.},
             keywords = {},
             annote = {  },
          }
     
    @article{Petrovic:2000:SIG,
             author = {Lena Petrovic and Brian Fujito and Adam Finkelstein   and Lance Williams  },
             title = {Shadows for Cel Animation},
             journal = {Proceedings of SIGGRAPH 2000},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {July 2000},
             editor = {},
             publisher = {ACM SIGGRAPH},
             pages = {},
             note = {Held in New Orleans, Louisianna.},
             keywords = {},
             annote = {  },
          }
    @article{Sander:2000:SIG,
             author = {Pedro V. Sander and Xianfeng Gu and 
             Steven J. Gortler and Hugues Hoppe and John Snyder },
             title = {Silhouette Clipping},
             journal = {Proceedings of SIGGRAPH 2000},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {July 2000},
             editor = {},
             publisher = {ACM SIGGRAPH},
             pages = {},
             note = {Held in New Orleans, Louisianna.},
             keywords = {},
             annote = {  },
          }
      
     @article{Zorin:2000:SIG,
             author = {Aaron Hertzmann and Denis Zorin  },
             title = {Illustrating Smooth Surfaces},
             journal = {Proceedings of SIGGRAPH 2000},
             series = {Computer Graphics Proceedings, Annual Conference Series},
             year = {July 2000},
             editor = {},
             publisher = {ACM SIGGRAPH},
             pages = {},
             note = {Held in New Orleans, Louisianna.},
             keywords = {},
             annote = {  },
          }  
    
    @inproceedings{Shiraishi:NPAR00,
      author = {Michio Shiraishi and Yasushi Yamaguchi },
      title =  { An Algorithm for Automatic Painterly Rendering based 
                       on Local Source Image Approximation},
      booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)},
      editor =   {},
      year =    {June 5-7,2000},
      publisher = {},
      address =   {Annecy, France},
      pages =    {},
      abstract="This paper presents a new method for the automatic
                painterly rendering.  This method synthesizes an
                impressive image with a hand crafted look from a source
                image such as a photograph.  This method generates
                rectangular brush strokes approximating the local regions
                of the source image with suitable locations, orientations,
                and sizes. These properties are calculated with the image
                moments of the color difference images, obtained by taking
                the difference between the local source images, and the
                stroke colors.  The method explicitly deals with not only
                intensity but also chromaticity of the source image.  The
                resulting image is composited with smaller strokes at the
                details while its flat regions are painted with larger
                ones.  The method is also able to control the density of
                strokes as well as their painting order based on their
                sizes.  The density is controlled by a dithering method
                with space-filling curves.  Painting process starts from
                the larger strokes and finishes with the finer ones.
                Because of the density control and the painting order the
                final image preserves the details of the source image.", 
    }
    
    @article{Winter2000,
       author = {RobertWinter},
       title = {Art by the Numbers},
       journal = {UCLA Magazine},
       year = {Spring 2000},
       editor = {},
       pages = {26--31},
       note = {}
    }
    
    @article{Barequet:1999,
       author = {G. Barequet and C. A. Duncan and M. T. Goodrich and S. Kumar and M. Pop},
       title = {Efficient perspective-accurate silhouette computation},
       journal = {Proceedings of the fifteenth annual symposium on Computational Geometry},
       year = {1999},
       editor = {},
       pages = {417--418},
       note = {}
    }
    
    @article{Deussen:1999:AIT,
       author = {Oliver Deussen and Joerg Harnel and Andreas Raab 
                 and Stefan Schlechtweg and Thomas Strothotte},
       title = {An Illustration Technique Using Hardware-Based Intersections},
       journal = {Graphics Interface '99},
       year = {June 1999},
       editor = {I. Scott MacKenzie and James Stewart},
       pages = {175--182},
       note = {ISBN 1-55860-632-7},
       keywords = {Non-Photorealistic Rendering, Illustration Techniques,
                   Arts, Graphics Hardware},
       annote = {We present a method for generating line drawings of
                 complex geometries in the style of crosshatched
                 illustrations. Hatching lines are generated by
                 intersecting the geometry with a set of
                 planes. Half-toning on the basis of the generated curves
                 is used to represent a given intensity
                 distribution. Computing a geometric skeleton allows us to
                 determine automatically the orientation of the
                 intersection planes for a wide variety of models. By
                 using predefined line styles different types of
                 illustrations can be generated.  Applications of the
                 method are discussed, examples are given. }, 
    }
     
    @Article{NPRCourse99,
       Author  = "Stuart Green and David Salesin and Simon Schofield and 
             Aaron Hertzmann and Peter Litwinowicz and Amy Gooch and 
             Cassidy Curtis and Bruce Gooch.",
       Title   = "{Non-Photorealistic Rendering}", 
       Journal= {SIGGRAPH '99 Non-Photorealistic Rendering Course Notes},
       Year    = 1999,
      
    }
    
    @Article{OpenGLCourse99,
       Author  = "David Blythe and Brad Grantham and Tom McReynolds and Scott R. Nelson",
       Title   = "{Advanced Graphics Programming Techniques Using OpenGL}", 
       Journal= {SIGGRAPH '99 Course},
       Year    = 1999,
      
    }
     
    @Article{gooc99,
       Author  = "Bruce Gooch and Peter-Pike Sloan and Amy Gooch
             and Peter Shirley and Richard Riesenfeld",
       Title   = "{Interactive Technical Illustration}", 
       Journal= {Interactive 3D Conference Proceedings},
       Year    = 1999,
       Volume  = {},
       Number  = {},
       Month = apr, 
       annote = {A rendering is an abstraction that favors, preserves, or
                 even emphasizes some qualities while sacrificing,
                 suppressing, or omitting other characteristics that are
                 not the focus of attention. Most computer graphics
                 rendering activities have been concerned with
                 photorealism, i.e., trying to emulate an image that looks
                 like a high-quality photograph. This laudable goal is
                 useful and appropriate in many applications, but not in
                 technical illustration where elucidation of structure and
                 technical information is the preeminent motivation.  This
                 calls for a different kind of abstraction in which
                 technical communication is central, but art and
                 appearance are still essential instruments toward this
                 end. Work that has been done on computer generated
                 technical illustrations has focused on static images, and
                 has not included all of the techniques used to hand draw
                 technical illustrations. A paradigm for the display of
                 technical illustrations in a dynamic environment is
                 presented. This display environment includes all of the
                 benefits of computer generated technical illustrations,
                 such as a clearer picture of shape, structure, and
                 material composition than traditional computer graphics
                 methods. It also includes the three-dimensional
                 interactive strength of modern display systems. This is
                 accomplished by using new algorithms for real time
                 drawing of silhouette curves, algorithms which solve a
                 number of the problems inherent in previous methods. We
                 incorporate current non-photorealistic lighting methods,
                 and augment them with new shadowing algorithms based on
                 accepted techniques used by artists and studies carried
                 out in human perception. },
    
    }
    
    @article{Hamel:1999:CAR,
       author = {J. Hamel and T. Strothotte},
       title = {Capturing and Re-Using Rendition Styles for 
           Non-Photorealistic Rendering},
       volume = {18},
       number = {3},
       journal = {Computer Graphics Forum},
       year = {September 1999},
       publisher = {Blackwell Publishers},
       pages = {173--182},
       note = {ISSN 1067-7055},
       annote = {Rendering high-quality non-photorealistic images of a
                 given geometric model is often associated with a
                 considerable amount of effort on the part of a user to
                 fine-tune the rendition. In this paper we introduce a
                 method and tools for re-using the user's effort invested
                 in one model for the rendering of other models.\\Our
                 method uses templates to describe rendition styles. The
                 paper gives a number of examples of the successful
                 transfer of styles from one model to another. }, 
    }
    
    @article{Igarashi:1999:TAS,
       author = {Takeo Igarashi and Satoshi Matsuoka and Hidehiko Tanaka},
       title = {Teddy: A Sketching Interface for 3D Freeform Design},
       journal = {Proceedings of SIGGRAPH 99},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1999},
       editor = {Alyn Rockwood},
       publisher = {Addison Wesley Longman},
       pages = {409--416},
       note = {ISBN 0-20148-560-5. Held in Los Angeles, California.},
       keywords = {3D modeling, sketching, pen-based systems, gestures, 
                   design, chordal axes, inflation},
       annote = {We present a sketching interface for quickly and easily
                 designing freeform models such as stuffed animals and
                 other rotund objects. The user draws several 2D freeform
                 strokes interactively on the screen and the system
                 automatically constructs plausible 3D polygonal
                 surfaces. Our system supports several modeling
                 operations, including the operation to construct a 3D
                 polygonal surface from a 2D silhouette drawn by the user:
                 it inflates the region surrounded by the silhouette
                 making wide areas fat, and narrow areas thin. Teddy, our
                 prototype system, is implemented as a Java program, and
                 the mesh construction is done in real-time on a standard
                 PC. Our informal user study showed that a first-time user
                 typically masters the operations within 10 minutes, and
                 can construct interesting 3D models within minutes. }, 
    }
    
    
    @article{Kowalski:1999:ARO,
       author = {Michael A. Kowalski and Lee Markosian and J. D. Northrup
                 and Lubomir Bourdev and Ronen Barzel and Loring S. Holden
                 and John Hughes},
       title = {Art-Based Rendering of Fur, Grass, and Trees},
       journal = {Proceedings of SIGGRAPH 99},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1999},
       editor = {Alyn Rockwood},
       publisher = {Addison Wesley Longman},
       pages = {433--438},
       note = {ISBN 0-20148-560-5. Held in Los Angeles, California.},
       keywords = {Non-photorealistic rendering, graftals, procedural textures},
       annote = {Artists and illustrators can evoke the complexity of fur
                 or vegetation with relatively few well-placed strokes. We
                 present an algorithm that uses strokes to render 3D
                 computer graphics scenes in a stylized manner suggesting
                 the complexity of the scene without representing it
                 explicitly. The basic algorithm is customizable to
                 produce a range of effects including fur, grass and
                 trees, as we demonstrate in this paper and accompanying
                 video. The algorithm is implemented within a broader
                 framework that supports procedural stroke-based textures
                 on polyhedral models. It renders mod-erately complex
                 scenes at multiple frames per second on current graphics
                 workstations, and provides some interframe coherence. },
    }
    
    @article{Markosian:1999:SAC,
       author = {Lee Markosian and Jonathan M. Cohen and Thomas Crulli and 
                 John F. Hughes},
       title = {Skin: A Constructive Approach to Modeling Free-form Shapes},
       journal = {Proceedings of SIGGRAPH 99},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1999},
       editor = {Alyn Rockwood},
       publisher = {Addison Wesley Longman},
       pages = {393--400},
       note = {ISBN 0-20148-560-5. Held in Los Angeles, California.},
       keywords = {Free-form modeling, meshes, subdivision, multiresolution}, 
       annote = {We present a new particle-based surface representation
                 with which a user can interactively sculpt free-form
                 surfaces. The particles maintain mesh connectivity and
                 operate under rules that lead them to form triangulations
                 with properties that make them suitable for use in
                 subdivision. A user interactively guides the particles,
                 which we call skin, to grow over a given collection of
                 polyhedral elements (or skeletons), yielding a smooth
                 surface (through subdivision) that approximates the
                 underlying skeletal shapes. Skin resembles blobby
                 modeling in the constructive approach to modeling it
                 supports, but allows a richer vocabulary of skeleton
                 shapes, supports sharp creases where desired, and
                 provides a convenient mechanism for adding
                 multiresolution surface detail. }, 
    
    }
    
    @article{Ostromoukhov:1999:DFE,
       author = {Victor Ostromoukhov},
       title = {Digital Facial Engraving},
       journal = {Proceedings of SIGGRAPH 99},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1999},
       editor = {Alyn Rockwood},
       publisher = {Addison Wesley Longman},
       pages = {417--424},
       note = {ISBN 0-20148-560-5. Held in Los Angeles, California.},
       keywords = {photorealistic rendering, nonphotorealistic rendering,
                   halftoning, dithering, digital engraving},
       annote = {This contribution introduces the basic techniques for
                 digital facial engraving, which imitates traditional
                 copperplate engraving. Inspired by traditional
                 techniques, we first establish a set of basic rules
                 thanks to which separate engraving layers are built on
                 the top of the original photo. Separate layers are merged
                 according to simple merging rules and according to range
                 shift/scale masks specially introduced for this
                 purpose. We illustrate the introduced technique by a set
                 of black/white and color engravings, showing different
                 features such as engraving-specific image enhancements,
                 mixing different regular engraving lines with mezzotint,
                 irregular perturbations of engraving lines etc. We
                 introduce the notion of engraving style which comprises a
                 set of separate engraving layers together with a set of
                 associated range shift/scale masks. The engraving style
                 helps to port the look and feel of one engraving to
                 another. Once different libraries of pre-defined mappable
                 engraving styles and an appropriate user interface are
                 added to the basic system, producing a decent gravure
                 starting from a simple digital photo will be a matter of
                 seconds. The engraving technique described in this
                 contribution opens new perspectives for digital art,
                 adding unprecedented power and precision to the
                 engraver's work. }, 
    }
    
    @article{Ostromoukhov:1999:MAA,
       author = {Victor Ostromoukhov and Roger D. Hersch},
       title = {Multi-Color and Artistic Dithering},
       journal = {Proceedings of SIGGRAPH 99},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {1999},
       month = {August},
       editor = {Alyn Rockwood},
       publisher = {Addison Wesley Longman},
       pages = {425--432},
       note = {ISBN 0-20148-560-5. Held in Los Angeles, California.},
       keywords = {color halftoning, artistic dithering, dither matrix
                   equilibration, non-standard inks, side by side printing},
       annote = {A multi-color dithering algorithm is proposed, which
                 converts a barycentric combination of color intensities
                 into a multi-color non-overlapping surface
                 coverage. Multi-color dithering is a generalization of
                 standard bi-level dithering. Combined with tetrahedral
                 color separation, multi-color dithering makes it possible
                 to print images made of a set of non-standard inks. In
                 contrast to most previous color halftoning methods,
                 multi-color dithering ensures by construction that the
                 different selected basic colors are printed side by
                 side. Multi-color dithering is applied to generate color
                 images whose screen dots are made of artistic shapes
                 (letters, symbols, ornaments, etc.). Two dither matrix
                 postprocessing techniques are developed, one for
                 enhancing the visibility of screen motives and one for
                 the local equilibration of large dither matrices. The
                 dither matrix equilibration process corrects disturbing
                 local intensity variations by taking dot gain and the
                 human visual system transfer function into
                 account. Thanks to the combination of the presented
                 techniques, high quality images can be produced, which
                 incorporate at the micro level the desired artistic
                 screens and at the macro level the full color
                 image. Applications include designs for advertisements
                 and posters as well as security printing. Multi-color
                 dithering also offers new perspectives for printing with
                 special inks, such as fluorescent and metallic inks. },
    }
    
    
    @article{Rademacher:1999:VDG,
       author = {Paul Rademacher},
       title = {View-Dependent Geometry},
       journal = {Proceedings of SIGGRAPH 99},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1999},
       editor = {Alyn Rockwood},
       publisher = {Addison Wesley Longman},
       pages = {439--446},
       note = {ISBN 0-20148-560-5. Held in Los Angeles, California.},
       keywords = {Cartoon animation, 3D animation, rendering, animation systems,
           non-photorealistic rendering, 3D blending},
       annote = {When constructing 3D geometry for use in cel animation,
                 the reference drawings of the object or character often
                 contain various view-specific distortions, which cannot
                 be captured with conventional 3D models. In this work we
                 present a technique called View-Dependent Geometry,
                 wherein a 3D model changes shape based on the direction
                 it is viewed from. A view-dependent model consists of a
                 base model, a set of key deformations (deformed versions
                 of the base model), and a set of corresponding key
                 viewpoints (which relate each 2D reference drawing to the
                 3D base model). Given an arbitrary viewpoint, our method
                 interpolates the key deformations to generate a 3D model
                 that is specific to the new viewpoint, thereby capturing
                 the view-dependent distortions of the reference
                 drawings. }, 
    }
    
    
    @InProceedings{raskar-temp,
       author= "Ramesh Raskar and Michael Cohen",
       title = "Image {P}recision {S}ilhouette {E}dges",
       booktitle = "Proc. 1999 ACM Symposium on Interactive 3D Graphics",
       year = "1999",
       month = apr,
       annote = {Finding and displaying silhouette edges is important in
                 applications ranging from computer vision to
                 nonphotorealistic rendering. To render visible silhouette
                 edges of a polygonal object in a scene from a given
                 viewpoint, we must first find all silhouette edges,
                 i.e. boundaries between adjacent front facing and
                 back-facing surfaces. This is followed by solving the
                 partial visibility problem so that only those parts of
                 silhouette edges, which are not occluded by interior of
                 any front facing surface, are rendered. The scene may
                 optionally be rendered with a lighting model. This paper
                 describes a simple general-purpose method to combine all
                 three operations for any scene composed of objects that
                 can be scan-converted. Using a depth buffer, the
                 rendering process computes the intersection of adjacent
                 front facing and back-facing surfaces in image space at
                 interactive rates. All operations are performed in
                 image-precision and hence special care is taken for the
                 limited numerical precision of the depth buffer. A
                 solution is suggested using view-dependent modification
                 of polygonal objects. The method does not require any
                 preprocessing or adjacency information and hence is
                 applicable for dynamic scenes.},
    
    }
    
    
    @TechReport{Shira:1999,
      author = "Michio Shiraishi and Yasushi Yamaguchi",
      title =  "Image Moment-Based Stroke Placement",
      year =   "1999",
      month =  May,
      pages =  "1--3",
      keywords =     "image, moment, paint, art, artistic ",
      number = "skapps3794",
      institution =  "University of Tokyo",
      address ="Tokyo Japan",
      abstract = "Painterly rendering algorithms synthesize the images 
                  with a hand-crafted touch from a source image of a real 
                  scene.  The current major scheme is based on Haeberli's 
                  method, which paints brush strokes on a canvas successively.
                  In our approach, each rectangular stroke is controlled by 
                  several attributes, namely, color, location, orientation, 
                  width, and length.  We propose an alternative method to 
                  determine these attributes so that the stroke nicely 
                  approximates a local region of the source image.", 
    
      annote = " This paper presents a method of using image moments to
                 capture the color, size, orientation, and a rough idea of
                 the texture needed for strokes in an automatic painting
                 system. Much of the math and a good breakdown of the
                 algorithm are presented.", }
    
    @article{Sousa:1999:CGP,
      author = {Mario Costa Sousa and John W. Buchanan},
      title = {Computer-Generated Graphite Pencil Rendering of 3D Polygonal Models},
      volume = {18},
      number = {3},
      journal = {Computer Graphics Forum},
      year = {September 1999},
      pages = {195--208},
      annote = {Researchers in non-photorealistic rendering have
                investigated the display of three-dimensional worlds using
                various display models. In particular, recent work has
                focused on the modeling of traditional artistic media and
                styles such as pen-and-ink illustration and watercolor
                painting. By providing 3D rendering systems that use these
                alternative display models users can generate traditional
                illustration renderings of their three-dimensional
                worlds. In this paper we present our graphite pencil 3D
                renderer. We have broken the problem of simulating pencil
                drawing down into four fundamental parts: (1) simulating
                the drawing materials (graphite pencil and drawing paper,
                blenders and kneaded eraser), (2) modeling the drawing
                primitives (individual pencil strokes and mark-making to
                create tones and textures), (3) simulating the basic
                rendering techniques used by artists and illustrators
                familiar with pencil rendering, and (4) modeling the
                control of the drawing composition. Each part builds upon
                the others and is essential to developing the framework
                for higher-level rendering methods and tools. In this
                paper we present parts 2, 3, and 4 of our research. We
                present non-photorealistic graphite pencil rendering
                methods for outlining and shading. We also present the
                control of drawing steps from preparatory sketches to
                finished rendering results. We demonstrate the
                capabilities of our approach with a variety of images
                generated from 3D models. },
    
    }
    
    @article{Sousa:1999:NRO,
      author = {Mario Costa Sousa and John W. Buchanan},
      title = {Observational Model of Blenders and Erasers in
               Computer-Generated Pencil Rendering},
      journal = {Graphics Interface '99},
      year = {1999},
      month = {June},
      editor = {I. Scott MacKenzie and James Stewart},
      pages = {157--166},
      note = {ISBN 1-55860-632-7},
      annote = {In this paper we present a blender and eraser model that
                extends our graphite pencil and paper model. This blender
                and eraser model enhances the rendering results producing
                realistic looking graphite pencil tones and textures. Our
                model is based on observations on the absorptive and
                dispersive properties of blenders and erasers interacting
                with lead material deposited over drawing paper. The
                parameters of our model are the particle composition of
                the lead over the paper, the texture of the paper, the
                position and shape of the blender and eraser, and the
                pressure applied to them. We demonstrate the capabilities
                of our approach with a variety of pencil swatches and
                compare them to digitized pencil drawings. We also present
                automatic and interactive image-based rendering results
                implementing traditional graphite pencil tone rendering
                methods. },
    }
    
    
    @article{Takagi:1999:VMO,
      author = {Saeko Takagi and Masayuki Nakajima and Issei Fujishiro},
      title = {Volumetric Modeling of Colored Pencil Drawing},
      journal = {Pacific Graphics '99},
      year = {1999},
      month = {October},
      note = {Held in Seoul, Korea.},
    }
    
    
    @article{Tumblin:1999:TMF,
      author = {Jack Tumblin and Greg Turk},
      title = {LCIS: A Boundary Hierarchy for Detail-Preserving Contrast Reduction},
      journal = {Proceedings of SIGGRAPH 99},
      series = {Computer Graphics Proceedings, Annual Conference Series},
      year = {August 1999},
      editor = {Alyn Rockwood},
      publisher = {Addison Wesley Longman},
      pages = {83--90},
      note = {ISBN 0-20148-560-5. Held in Los Angeles, California.},
      keywords = {Signal Processing, Displays, Non-Realistic Rendering, 
      Level Of Detail Algorithms, Radiosity, Weird Math},
      annote = {High contrast scenes are difficult to depict on low
          contrast displays without loss of important fine details and
          textures. Skilled artists preserve these details by drawing
          scene contents in coarse-to-fine order using a hierarchy of
          scene boundaries and shadings. We build a similar hierarchy
          using multiple instances of a new low curvature image simplifier
          (LCIS), a partial differential equation inspired by anisotropic
          diffusion. Each LCIS reduces the scene to many smooth regions
          that are bounded by sharp gradient discontinuities, and a single
          parameter K chosen for each LCIS controls region size and
          boundary complexity. With a few chosen K values (K1 > K2 >
          K3...) LCIS makes a set of progressively simpler images, and
          image differences form a hierarchy of increasingly important
          details, boundaries and large features.\\ We construct a high
          detail, low contrast display image from this hierarchy by
          compressing only the large features, then adding back all small
          details. Unlike linear filter hierarchies such as wavelets,
          filter banks, or image pyramids, LCIS hierarchies do not smooth
          across scene boundaries, avoiding "halo" artifacts common to
          previous contrast reducing methods and some tone reproduction
          operators.\\ We demonstrate LCIS effectiveness on several
          example images. }, 
    }
    
    @article{Veryovka:1999:HWI,
       author = {Oleg Veryovka and John W. Buchanan},
       title = {Halftoning With Image-Based Dither Screens},
       journal = {Graphics Interface '99},
       year = {June 1999},
       editor = {I. Scott MacKenzie and James Stewart},
       pages = {167--174},
       note = {ISBN 1-55860-632-7},
       keywords = {Halftoning, texture processing, artistic screening,
                   non-photorealistic rendering},
       annote = {Continuous tone imaces must be halftoned to be displayed
                 on binary output devices such as printers. The ordered
                 dither algorithm is a popular approach to halftoning.
                 This algorithm uses a threshold matrix to approximate
                 gray scale values. The arrangement of thresholds in the
                 matrix determines texture artifacts introduced into the
                 halftoned image.  Thus, the challenge of research in
                 ordered dithering is to find a matrix that results in the
                 least visible texture artifacts.\\ In this work we
                 control the halftoning texture by generating a threshold
                 matrix from an arbitrary image. We demonstrate that
                 processing images using adaptive histogram equalization
                 results in pixel distributions similar to traditional
                 dither screens. Ordered dithering with the resulting
                 threshold matrix enables us to define texture in the
                 halftoned image. We control the appearance of this
                 texture by a combination of the ordered dither algorithm
                 with an error diffusion process.\\ We present
                 applications of the image-based dither screens to both
                 photorealistic and artistic rendering. In the case of
                 photoreatistic tone reproduction this technique preserves
                 textures and edges of the original imaae. The ability to
                 define an arbitrary texture enables us to introduce a
                 variety of artistic effects. A halftoned image can be
                 embossed with another image, texture, or text. Also,
                 halftoning with textures clipped from the existing art
                 works approximates the look of traditional illustration
                 media. }, 
    }
    
    @mastersThesis{Wong:1999,
      author = "Eric Wong",
      title =  "Artistic Rendering of Portrait Photographs",
      year =   "1999",
      keywords =     "image, portrait, photographs, rendering, paint, artistic ",
      school =  "Cornell University",
      abstract = "In this thesis, we present a semi-automatic process to
                  artistically render portrait photographs in a charcoal
                  style.  The software system requires the user to coach
                  the process by identifying regions and edges in the
                  portrait.  With their information and a set of selected
                  parameters, the user can quickly generate an artistic
                  charcoal sketch.  In general, our system produces a
                  charcoal image by rendering the following five features
                  of a portrait photograph: 1) the background area, 2) the
                  hair, 3) the edges and lines, 4) the facial features,
                  and 5) the facial tone.  Although we compute the vertex
                  points that compose the line segments in the final
                  image, our system relies on an external software
                  application to render these lines in a charcoal style.
                  In order to render the hair region in the second process
                  step above, we developed a novel image processing
                  operation based on the Hough transform to find the
                  orientation of each point tin the hair region. ",
    
    
      annote = " This thesis presents an interactive method for generating 
                 charcoal style drawn portraits.  One thing to note is that 
                 quite a bit of user interaction is needed at each step in the 
                 process.  Also, the idea of interactive portraits or animated
                 portraits has not been addressed.  One good note is the idea 
                 of having the level of abstraction match the stage of the 
                 design process was finally expressed. The software engineering 
                 on this thesis was well done, and the process is broken down 
                 into reasonable pieces that could be automated.  In particular, 
                 the automation of later parts of the process may only depend 
                 on earlier parts being automated.",
    }
    
    @article{Zhang:1999:SCA,
    
       author = {Qing Zhang and Youetsu Sato and Jun-ya Takahashi and
                 Kazunobu Muraoka and Norishige Chiba},
       title = {Simple cellular automaton-based simulation of ink
                behaviour and its application to Suibokuga-like 3D
                rendering of trees},
       volume = {10},
       number = {1},
       journal = {The Journal of Visualization and Computer Animation},
       year = {January - March 1999},
       publisher = {John Wiley & Sons},
       pages = {27--37},
       note = {ISSN 1049-8907},
       keywords = {non-photorealistic rendering; Suibokuga-like rendering;
                   simulation of ink diffusion; cellular automaton},
    
       annote = {Suibokuga is a style of monochrome painting characterized
                 by the use of Chinese black ink (sumi), a complex
                 interaction between brush, ink and paper, and such visual
                 features as Noutan (shade), Kasure (scratchiness), and
                 Nijimi (blur). In this paper we present a simple
                 behavioural model of water and ink particles based on a
                 2D cellular automaton computational model, and its
                 application to a Suibokuga-like rendering of 3D trees. },
    }
    @article{bremmer1998,
       author = { David J. Bremer  and  John F. Hughes  },
       title = {Rapid Approximate Silhouette Rendering of Implicit Surfaces},
       journal = {Proceedings of Implicit Surfaces '98},
       series = {},
       year = {June 1998},
       editor = {},
       publisher = {},
       pages = {155--164},
       note = {},
       keywords = {},
       annote = {}, 
    }
    
    @article{Correa:1998:TMF,
       author = {Wagner Toledo Corr{\^{e}}a and Robert J. Jensen and Craig
                 E. Thayer and Adam Finkelstein},
       title = {Texture Mapping for Cel Animation},
       journal = {Proceedings of SIGGRAPH 98},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {July 1998},
       editor = {Michael Cohen},
       publisher = {Addison Wesley},
       pages = {435--446},
       note = {ISBN 0-89791-999-8. Held in Orlando, Florida.},
       keywords = {Cel animation, texture mapping, silhouette detection,
                   warp, metamorphosis, morph, non-photorealistic
                   rendering},
       annote = {We present a method for applying complex textures to
                 hand-drawn characters in cel animation. The method
                 correlates features in a simple, textured, 3-D model with
                 features on a hand-drawn figure, and then distorts the
                 model to conform to the hand-drawn artwork. The process
                 uses two new algorithms: a silhouette detection scheme
                 and a depth-preserving warp. The silhouette detection
                 algorithm is simple and efficient, and it produces
                 continuous, smooth, visible contours on a 3-D model. The
                 warp distorts the model in only two dimensions to match
                 the artwork from a given camera perspective, yet
                 preserves 3-D effects such as self-occlusion and
                 foreshortening. The entire process allows animators to
                 combine complex textures with hand-drawn artwork,
                 leveraging the strengths of 3-D computer graphics while
                 retaining the expressiveness of traditional hand-drawn
                 cel animation. }, 
    }
    
    @mastersThesis{Coutts:1998,
       author = "Richard M. Coutts",
       title =  "Conceptual modeling and rendering techniques for architectural design.",
       year =   "1998",
       keywords =     "image, portrait, photographs, rendering, paint, artistic ",
       school =  "Cornell University",
       annote = {Todays design professions are not integrating the
                 computer into their workplace as successfully as more
                 technical professionals.  It is tempting to attribute
                 this to the fact that artists and architects are not as
                 technically savvy as engineers and scientists.  Closer
                 inspection reveals, however, that current software
                 applications simply do not fit their needs.
    
                 Three problematic areas are identified in this thesis in
                 current design software. (1) Human-computer interfaces
                 are to cumbersome for design.  (2) the current
                 human-computer interfaces do not facilitate transitioning
                 between conceptuall drawings and computer models.  (3)
                 Current omputer rendering styles are not abstract enough
                 for visualizing incomplete designs.  These shortcomings
                 are alleviated here by introducing a new human acomputer
                 interface and sketch rendering tecniques.
    
                 A solid modeler was written for this thesis to address
                 the human-computer interface issues.  Currently,
                 architects and designers use traditional media - e.g.,
                 clay, chipboard, and sketches - in preliminary design.
                 For a solid modeler to ccompete with these materials, it
                 must be as simple to use.  Our modeler;s interface
                 approaches this goal by incorporating a surface cursor
                 that feels its way along the models surface, giving the
                 designer much needed visuall cues as to the cursor's
                 location in three diminsions.
    
                 The need for more abstract rendering styles is addressed
                 by presenting a new technique for generating sketch
                 renderings.  These renderings approximate the look and
                 feel of conventional hand drawings.  The algorithims
                 presented here simulate an artist's hatch markings and
                 vectored streamlines.  The streamlines are calculated in
                 a two dimentional vector field generated by projecting
                 three dimensional surface flow onto the image plane.  A
                 global illumination image is used as a tone map to
                 control the hatching density.  Because the algorithims
                 operate on strictly two-dimensional data extracted from the
                 three-dimensional model, they are robust and simple to
                 implement.  Several new support algorithims, including a
                 new one-pass streamline algorithim that approximates both
                 denisity and direction, are described.},
    
     }
    
    @InProceedings{Curtis98,
       author = "Cassidy Curtis",
       title = "Loose and {S}ketchy {A}nimation",
       booktitle = "SIGGRAPH 98: Conference Abstracts and Applications",
       year = "1998",
       pages = "317",
       annote = {In naritive charactor animaiton, engaging the viewer and
                 conveying emotion and personality are of the highest
                 importance.  Early in the development of the medium,
                 animators learned that an effective way to achieve these
                 goals was to "present a unified single idea with nothing
                 complicated extraneous, or contradictory in its makeup."
                 But this principle is seldom applied successfully in
                 computer animation because of the demands of
                 photorealistic rendering.
    
                 Photrealism , liike pornography, leaves nothing to the
                 imagination.  It presents the viewer with a world of
                 objects omplete with volume and texture, which is far
                 more information that the viewer needs to get the point.
                 FFurthermore, unless great effort is devoted to every
                 detail of modeling, shading, and lighting, much fo that
                 information will actually contradict the central idea,
                 distracting the viewer.  The need to cancel out these
                 spurious impressions places an unreasonable demand on the
                 animator.},
    
    }
    
    @Article{Elber:1998:LAI,
       author =   "Gershon Elber",
       title =    "Line {A}rt {I}llustrations of {P}arametric and {I}mplicit {F}orms",
       journal =      "IEEE Transactions on Visualization and Computer Graphics",
       year =     "1998",
       volume =   "4",
       number =   "1",
       month =    jan # " -- " # mar,
       note =     "ISSN 1077-2626",
       keywords =     "Sketches, illustrations, line drawings, freeform
              surfaces, NURBs, implicit forms, surface coverage,
              printing",
       annote =   "A technique is presented for line art rendering of
              scenes composed of freeform surfaces. The line art that
              is created for parametric surfaces is practically
              intrinsic and is globally invariant to changes in the
              surface parameterization. This method is equally
              applicable for line art rendering of implicit forms,
              creating a unified line art rendering method for both
              parametric and implicit forms. This added flexibility
              exposes a new horizon of special, parameterization
              independent, line art effects. Moreover, the production
              of the line art illustrations can be combined with
              traditional rendering techniques such as transparency
              and texture mapping. Examples that demonstrate the
              capabilities of the proposed approach are presented for
              both the parametric and implicit forms.",
    
         }
    
    @article{Gooch:1998:ANL,
       author = {Amy Gooch and Bruce Gooch and Peter Shirley and Elaine Cohen},
       title = {A Non-Photorealistic Lighting Model for Automatic 
            Technical Illustration},
       journal = {Proceedings of SIGGRAPH 98},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {July 1998},
       editor = {Michael Cohen},
       publisher = {ACM SIGGRAPH},
       pages = {447--452},
       note = {ISBN 0-89791-999-8. Held in Orlando, Florida.},
       keywords = {illustration, non-photorealistic rendering,
           silhouettes, lighting models, tone, color, shading},
       annote = {Phong-shaded 3D imagery does not provide geometric
             information of the same richness as human-drawn technical
             illustrations. A non-photorealistic lighting model is
             presented that attempts to narrow this gap. The model is
             based on practice in traditional technical illustration,
             where the lighting model uses both luminance and changes
             in hue to indicate surface orientation, reserving extreme
             lights and darks for edge lines and highlights. The
             lighting model allows shading to occur only in mid-tones
             so that edge lines and highlights remain visually
             prominent. In addition, we show how this lighting model
             is modified when portraying models of metal
             objects. These illustration methods give a clearer
             picture of shape, structure, and material composition
             than traditional computer graphics methods. }, 
    }
    
    @MastersThesis{Gooch:1998:thesis,
       Author="Gooch, Amy A.",
       School="University of Utah",
       Title="Interactive Non-photorealistic Technical Illustration",
       Year="1998",
       Month="December",
       Attributions = "", 
       Abstract = "Current interactive modeling systems allow users to
                   view models in wireframe or Phong-shaded images.
                   However, the wireframe is based on the model's
                   parameterization, and a model's features may get lost
                   in a nest of lines. Alone, a fully rendered image may
                   not provide enough useful information about the
                   structure or model features.  Human technical
                   illustrators follow certain visual conventions that are
                   unlike Phong-shaded or wireframe renderings, and the
                   drawings they produce are subjectively superior to
                   conventional computer renderings.  This thesis explores
                   lighting, shading, and line illustration conventions
                   used by technical illustrators.  These conventions are
                   implemented in a modeling system to create a new method
                   of displaying and viewing complex NURBS models.  In
                   particular, silhouettes and edge lines are drawn in a
                   manner similar to pen-and-ink drawings, and a shading
                   algorithm is used that is similar to ink-wash or
                   air-brush renderings for areas inside the silhouettes.
                   This shading has a low intensity variation so that the
                   black silhouettes remain visually distinct, and it has
                   a cool-to-warm hue transition to help accent surface
                   orientation.  Applying these illustration methods
                   produces images that are closer to human-drawn
                   illustrations than is provided by traditional computer
                   graphics approaches.",  
    }
    
    @article{Hertzmann:1998:PRW,
      author = {Aaron Hertzmann},
      title = {Painterly Rendering with Curved Brush Strokes of Multiple Sizes},
      journal = {Proceedings of SIGGRAPH 98},
      year = {July 1998},
      editor = {Michael Cohen},
      pages = {453--460},
      keywords = {non-photorealistic rendering},
      annote = {We present a new method for creating an image with a
                hand-painted appearance from a photograph, and a new
                approach to designing styles of illustration.  We "paint"
                an image with a series of spline brush strokes. \\ Brush
                strokes are chosen to match colors in a source image. A
                painting is built up in a series of layers, starting with
                a rough sketch drawn with a large brush. The sketch is
                painted over with progressively smaller brushes, but only
                in areas where the sketch differs from the blurred source
                image. Thus, visual emphasis in the painting corresponds
                roughly to the spatial energy present in the source
                image. We demonstrate a technique for painting with long,
                curved brush strokes, aligned to normals of image
                gradients.  Thus we begin to explore the expressive
                quality of complex brush strokes. Rather than process
                images with a single manner of painting, we present a
                framework for describing a wide range of visual styles. A
                style is described as an intuitive set of parameters to
                the painting algorithm that a designer can adjust to vary
                the style of painting. We show examples of images rendered
                with different styles, and discuss long-term goals for
                expressive rendering styles as a general-purpose design
                tool for artists and animators. }, 
    }
    
    @InProceedings{Masuch:1998:AFF,
      author =       {Maic Masuch and Lars Schumann and Stefan Schlechtweg},
      title =        {{A}nimating {F}rame-to-{F}rame {C}onsistent {L}ine {D}rawings
                      for {I}llustrative {P}urposes},
      booktitle =    {Simulation und Animation '98},
      editor =       {Peter Lorenz and Bernhard Preim},
      year =         {1998},
      publisher =    {SCS Europe},
      address =      {Erlangen, Ghent},
      pages =        {101--112},
      annote = {We present a system for rendering 3D animations in the
                style of line drawings. We use a highly parameterized line
                model in order to determine the appearance of a line. This
                model allows us to render characteristic line deviations
                that remain--in contrast to existing non-photorealistic
                rendering systems--frame coherent. Other inconsistencies
                which result from intersection and visibility changes
                during an animation are prevented by a path reconstruction
                method. Furthermore, we implemented a keyframing for
                linestyle parameters which enables us to extend
                illustration techniques like simplification of a scene or
                the placement of emphasis on certain objects to the field
                of 3D computer animation. },
    
    }
    
    @article{Snyder1998,
       author = {A. W. Snyder and H. B. Barlow},
       title = {Revealing the artist's touch},
       volume = {331},
       number = {14},
       journal = {Nature},
       year = {1998},
       editor = {},
       publisher = {},
       pages = {117--118},
       annote = {Is there a unifying conceptual framework for
                 understanding human visual-information processing, one
                 that explains the occurence of illusions such as those of
                 Ramachandran on page 163 of this issue?  Or is it better
                 to regard our visual system as a mosaic of unrelated
                 strategies, one ffor every special taks? An animal needs
                 to make rapid decisions about what objects are where in
                 its surroundings, but it has only a few neurons at its
                 disposal: this strongly suggests that eh brain should
                 first simplify processing for detection and recognition
                 fo objects, and then report its findings with the utmost
                 economy.  WE propose that these two principles provide a
                 unifying interpretation of existing perceptual data and
                 will enable us to place new results in a proper
                 perspective.},
    }
    
    @article{Streit:1998:IDH,
       author = {L. M. Streit and J. W. Buchanan},
       title = {Importance Driven Halftoning},
       volume = {17},
       number = {3},
       journal = {Computer Graphics Forum},
       year = {1998},
       editor = {N. Ferreira and M. G{\"{o}}bel},
       publisher = {Blackwell Publishers},
       pages = {207--218},
       note = {ISSN 1067-7055},
       keywords = {halftoning, bandpass pyramid, importance function,
                   limited resource rendering, non-photorealistic
                   rendering, traditional halftoning, drawing primitive,
                   multiresolution representations},
       annote = {Most halftoning techniques have been primarily concerned
                 with achieving an accurate reproduction of local
                 grayscale intensities while avoiding the introduction of
                 artifacts. A second concern in halftoning has been the
                 preservation of edges in the halftoned image. In this
                 paper we will introduce a new halftoning technique that
                 utilizes a bandpass pyramid to achieve an accurate
                 reproduction of important attributes in the image.  Ink
                 is distributed through the bandpass pyramidprimarily
                 according to a user defined importance function. This
                 technique has three main characteristics. First, our
                 technique can produce results similar to many other
                 halftoning techniques by allowing a generic importance
                 function to be specified. If the chosen importance
                 function is average intensity we obtain results similar
                 to traditional halftoning. We also show how the
                 importance function can be changed to highlight areas
                 with high variance. Second, in addition to changing the
                 importancefunction, the drawing primitives can also be
                 changed. By using line segments instead of single pixels
                 as drawing primitives we illustrate how edge enhancement
                 can be achieved. Third, this technique allows the user to
                 easily limit the number drawing primitives used This is
                 useful in limited resource rendering. \\ In addition to
                 providing a tailorable halftoning technique our method
                 can easily be adapted to produce two tone
                 non-photorealistic (NPR) images. We illustrate this by
                 showing how sketched effects can be achieved bv aligning
                 the drawing primitives according to different image
                 attributes. }
    }
    
    @InProceedings{Teece98,
       author = "Daniel Teece",
       title = "{3D} {P}ainting for {N}on-{P}hotorealistic {R}endering",
       booktitle = "SIGGRAPH 98: Conference Abstracts and Applications",
       year = "1998",
       pages = "248",
       annote = {The 3D Expressive Painter is an interactive, expressive
                 3D painting and rendering system intended for us in
                 production of hand-drawn natural-media-style animations.
                 By using some imported scene geometry, created in a
                 general-purpose modeler, the system allows interactive
                 placement of paint strokes in 3D.  The user is able to
                 rotate the scene, select a suitable viewing angle, and
                 paint from the desired direction, eith the depth values
                 for stroke positions calculated from the imported scene.
                 High level effects can be applied to objects within the
                 scene (for example, tracing determined "key edges" with
                 pencil strokes of filling surfaces with a solid color). },
    
    
    
    }
    
    @phdthesis{Raab1998,
       author = "A. Rabb",
       title = "{Techniques for Interacting with and Visualization of Geometric Models}",
       school = "Otto-von-Guericke University of Magdeburg",
       year	= "1998",
       address = "",
       month = {},
       note	= {}
    } 
    @phdthesis{Teece98b,
       author = "Daniel Teece",
       title = "{Three Dimensional Interactive Non-Photorealistic Rendering}",
       school = "University of Sheffield",
       year	= "1998",
       address = "England",
       month = {},
       note	= {}
    } 
    
    
    @article{Visvalingam:1998:AFS,
             author = {Mahes Visvalingam and Kurt Dowson},
             title = {Algorithms for sketching surfaces},
             volume = {22 },
             number = {2-3},
             journal = {Computers \& Graphics},
             year = {1998},
             month = {March},
             publisher = {Pergamon Press / Elsevier Science},
             pages = {269--280},
             note = {ISSN 0097-8493},
          }
    
    @InProceedings{Wong:1998:CGF,
       author =   "Michael T. Wong and Douglas E. Zongker and David H. Salesin",
       title =    "Computer-{G}enerated {F}loral {O}rnament",
       booktitle =    "SIGGRAPH 98 Conference Proceedings",
       editor =   "Michael Cohen",
       series =   "Annual Conference Series",
       year =     "1998",
       organization = "ACM SIGGRAPH",
       publisher =    "Addison Wesley",
       month =    jul,
       pages =    "423--434",
       note =     "ISBN 0-89791-999-8",
       keywords =     "adaptive clip art, conventionalization, pattern
              generation, plant development, ornamentation, texture
              generation",
       annote = "This paper describes some of the principles of
                 traditional floral ornamental design, and explores ways
                 in which these designs can be created algorithmically.
                 It introduces the idea of 'adaptive clip art,' which
                 encapsulates the rules for creating a specific ornamental
                 pattern. Adaptive clip art can be used to generate
                 patterns that are tailored to fit a particularly shaped
                 region of the plane. If the region is resized or
                 reshaped, the ornament can be automatically re-generated
                 to fill this new area in an appropriate way. Our
                 ornamental patterns are created in two steps: first, the
                 geometry of the pattern is generated as a set of
                 two-dimensional curves and filled boundaries; second,
                 this geometry is rendered in any number of styles. We
                 demonstrate our approach with a variety of floral
                 ornamental designs.",
         }
    
    @article{Balder:OM:1997,
            author = {Norman I. Balder and Andrew S. Glassner},
            title = {3D object modeling},
            volume = {18},
            number = {3},
            journal = {SIGGRAPH 97 Introduction to COmputer Graphics Course Notes},
            year = {1997},
            month = {August},
            editor = {},
            pages = {},
            note = {},
            keywords = {},
            annote = {},
     }
    
    @Article{Claes97,
       Author  = "Johan Claes and Patrick Monsieurs and 
                  Frank Van Reeth and Eddy Flerackers",
       Title   = "{Rendering Pen-drawings of 3D scenes on networked processors}", 
       Journal= {WSCG '97 proceedings},
       Year    = 1997,
       Volume  = {1},
       Number  = {},
       Month = feb,
       pages = {} 
    }
     
     
    @article{Coutts:1997,
      author = "Richard Coutts and Donald P. Greenberg",
      title = "Rendering with streamlines",
      journal = {Unpublished},
      Year    = 1997,
      annote = {We introduce a new technique for creating
                non-photorealistic images from computer models.  The
                technique uses two dimensional, vectored streamlines to
                approximate the hatch markings of a traditional artist.
                The streamlines are calculated in a two-dimensional vector
                field that is generated by projectiing three-dimensional
                surface flow onto the image plane.  Aray-traced image is
                used as a tone map to control the density fo the hatching.
                Anew one-pass streamline algorithim is introduced that
                approximates both density and direction.  The technique is
                implemented in a fully automatic system that renders
                free-form three-dimensional objects with varying levels of
                sketchiness.},
    
    }
    
    @article{Curtis:1997,
      author = "Cassidy J. Curtis and Sean E. Anderson and Joshua E. Seims and Kurt 
                W. Fleischer and David H. Salesin",
      title = "Computer-Generated Watercolor",
      journal = {Proceedings of SIGGRAPH 97},
      month = "August",
      pages = "pages 421--430",
      year = "1997",
      keywords =     "Fluid simulation, glazing, illustration, Kubelka-Munk, 
                      non-photorealistic rendering, optical compositing, painting, 
                      pigments, watercolor",
      abstract = "This paper describes the various artistic effects of watercolor 
                  and shows how they can be simulated automaticly.  Our watercolor 
                  model is based on an ordered set of translucent glazes, which are
                  created independently using a shallow-water fluid simulation.  
                  We use a Kubelka-Munk compositing model for simulating the 
                  optical effect of the superimposed glazes.  We demonstrate how 
                  computer generated watercolor can be used in three different 
                  application:  as part of an interactive watercolor paint system, 
                  as a method for automatic image watercolorization, and as a 
                  mechanism for non-photorealistic rendering of three-dimensional 
                  scenes. ", 
    
      annote = "  This paper presents a method for simulating water color painting.
                  The method uses a complex method of modeling fluid flow, and 
                  pigment transportation.  By doing this they get away with using 
                  simple models for the paper and brushes.  This paper also presents
                  a method for automatic painting, based on an image by using image
                  differences. ",
    
    }
     
    @article{Interrante:1997:ISS,
            author = {Victoria L. Interrante},
            title = {Illustrating Surface Shape in Volume Data via
         Principal Direction-Driven 3D Line Integral Convolution},
            journal = {Proceedings of SIGGRAPH 97},
            series = {Computer Graphics Proceedings, Annual Conference
         Series},
            year = {1997},
            month = {August},
            editor = {Turner Whitted},
            publisher = {Addison Wesley},
            pages = {109--116},
            note = {ISBN 0-89791-896-7. Held in Los Angeles, California.},
            keywords = {visualization, transparent surfaces, shape
         representation, principal directions, stroke textures, line
         integral convolution, solid texture, isosurfaces, volume
         rendering},
            annote = {This paper describes how the set of principal
         directions and principal curvatures can be understood to define a
         natural "flow" over the surface of an object and, as such, can be
         used to guide the placement of the lines of a stroke texture that
         seeks to represent 3D shape in a perceptually intuitive way. The
         driving application for this work is the visualization of layered
         isovalue surfaces in volume data, where the particular identity of
         an individual surface is not generally known a priori and
         observers will typically wish to view a variety of different level
         surfaces from the same distribution, superimposed over underlying
         opaque structures. This paper describes how, by advecting an
         evenly distributed set of tiny opaque particles, and the empty
         space between them, via 3D line integral convolution through the
         vector field defined by the principal directions and principal
         curvatures of the level surfaces passing through each gridpoint of
         a 3D volume, it is possible to generate a single scan-converted
         solid stroke texture that can be used to illustrate the essential
         shape information of any level surface in the data. By redefining
         the length of the filter kernel according to the magnitude of the
         maximum principal curvature of the level surface at each point
         around which the convolution is applied, one can generate longer
         strokes over more the highly curved areas, where the directional
         information is both most stable and most relevant, and at the same
         time downplay the visual impact of the directional information
         indicated by the stroke texture in the flatter regions. In a
         voxel-based approach such as this one, stroke narrowness will be
         constrained by the resolution of the volume within which the
         texture is represented. However, by adaptively indexing into
         multiple pre-computed texture volumes, obtained by advecting
         particles of increasing sizes, one may selectively widen the
         strokes at any point by a variable amount, determined at the time
         of rendering, to reflect shading information or any other function
         defined over the volume data. },
         } 
    
    @article{Jobard:1997,
            author = {Bruno Jobard and Wilfrid Lefer},
            title = {Creating evenly-spaced streamlines of arbitrary density},
            journal = {Proc. of 8th Eurographics Workshop on Visualization in Scientific Computing},
            series = {},
            year = {1997},
            month = {},
            editor = {},
            publisher = {},
            pages = {45--55},
            note = {},
            keywords = {},
    } 
    
    @article{Litwinowicz:1997:PIA,
       author = {Peter Litwinowicz},
       title = {Processing Images and Video for an Impressionist Effect},
       journal = {Proceedings of SIGGRAPH 97},
       year = {August 1997},
       pages = {407--414},
       annote = {This paper describes a technique that transforms ordinary
                 video segments into animations that have a hand-painted
                 look. Our method is the first to exploit temporal
                 coherence in video clips to design an automatic filter
                 with a hand-drawn animation quality, in this case, one
                 that produces an Impressionist effect.  Off-the-shelf
                 image processing and rendering techniques are employed,
                 modified and combined in a novel way. This paper proceeds
                 through the process step by step, providing helpful hints
                 for tuning the off-the-shelf parts as well as describing
                 the new techniques and bookkeeping used to glue the parts
                 together. }, 
    }
    
    @article{Luebke:1997:VSO,
            author = {David Luebke and Carl Erikson},
            title = {View-Dependent Simplification of Arbitrary Polygonal Environments},
            journal = {Proceedings of SIGGRAPH 97},
            series = {Computer Graphics Proceedings, Annual Conference Series},
            year = {1997},
            month = {August},
            editor = {Turner Whitted},
            publisher = {Addison Wesley},
            pages = {199--208},
            note = {ISBN 0-89791-896-7. Held in Los Angeles, California.},
            keywords = {polygonal simplification, level of detail, view dependent
         rendering},
            annote = {Hierarchical dynamic simplification (HDS) is a new
         approach to the problem of simplifying arbitrary polygonal
         environments. HDS operates dynamically, retessellating the scene
         continuously as the user's viewing position shifts, and
         adaptively, processing the entire database without first
         decomposing the environment into individual objects. The
         resulting system allows real-time display of very complex
         polygonal CAD models consisting of thousands of parts and
         hundreds of thousands of polygons. HDS supports various
         preprocessing algorithms and various run-time criteria, providing
         a general framework for dynamic view-dependent
         simplification. Briefly, HDS works by clustering vertices
         together in a hiera rchical fashion. The simplification process
         continuously queries this hierarchy to generate a scene
         containing only those polygons that are important from the
         current viewpoint. When the volume of space associated with a
         vertex cluster occupies less than a user-specified amount of the
         screen, all vertices within that cluster are collapsed together
         and degenerate polygons filtered out. HDS maintains an active
         list of visible polygons for rendering. Since frame-to-frame
         movements typically involve small changes in viewpoint, and
         therefore modify the active list by only a few polygons, the
         method takes advantage of temporal coherence for greater speed.
         },
         }
    
    @article{Markosian:1997:RNR,
       author = {Lee Markosian and Michael A. Kowalski and Samuel
                 J. Trychin and Lubomir D.  Bourdev and Daniel Goldstein
                 and John F. Hughes},
       title = {Real-Time Nonphotorealistic Rendering},
       journal = {Proceedings of SIGGRAPH 97},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1997},
       editor = {Turner Whitted},
       publisher = {Addison Wesley},
       pages = {415--420},
       note = {ISBN 0-89791-896-7. Held in Los Angeles, California.},
       keywords = {non-photorealistic rendering},
       annote = {Nonphotorealistic rendering (NPR) can help make
                 comprehensible but simple pictures of complicated objects
                 by employing an economy of line. But current
                 nonphotorealistic rendering is primarily a batch
                 process. This paper presents a real-time
                 nonphotorealistic renderer that deliberately trades
                 accuracy and detail for speed. Our renderer uses a method
                 for determining visible lines and surfaces which is a
                 modification of Appel's hidden-line algorithm, with
                 improvements which are based on the topology of singular
                 maps of a surface into the plane. The method we describe
                 for determining visibility has the potential to be used
                 in any NPR system that requires a description of visible
                 lines or surfaces in the scene. The major contribution of
                 this paper is thus to describe a tool which can
                 significantly improve the performance of these
                 systems. We demonstrate the system with several
                 nonphotorealistic rendering styles, all of which operate
                 on complex models at interactive frame rates. }, 
    }
    
    @InProceedings{Masuch:1997:DDA,
      author =       {Maic Masuch and Stefan Schlechtweg and Bert Sch{\"o}nw{\"a}lder},
      title =        {daLi! -- {D}rawing {A}nimated {L}ines!},
      booktitle =    {Simulation und Animation '97},
      editor =       {O. Deussen and P. Lorenz},
      year =         {1997},
      publisher =    {SCS Europe},
      address =      {Erlangen, Ghent},
      pages =        {87--96},
      annote = {We present an animation system for the creation of
               non-photorealistic 3D animations. Our system daLi! is able
               to render images using a common 3D model as input. This
               model may be enriched with additional information
               concerning for instance hierarchy, structure and
               presentation style. The rendering is done analytically,
               which means the output is resolution independent. It
               results in a series of images that depict the animation
               using line-drawings. The implementation of daLi! was
               completely done in Smalltalk. },
    }
    
    @article{Salisbury:1997:OTF,
       author = {Michael P. Salisbury and Michael T. Wong and John F. Hughes 
                 and David H. Salesin},
       title = {Orientable Textures for Image-Based Pen-and-Ink Illustration},
       journal = {Proceedings of SIGGRAPH 97},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1997},
       editor = {Turner Whitted},
       publisher = {Addison Wesley},
       pages = {401--406},
       note = {ISBN 0-89791-896-7. Held in Los Angeles, California.},
       keywords = {Controlled-density hatching, direction field,
                   image-based rendering, non-photorealistic rendering,
                   scale-dependent rendering, stroke textures},
       annote = {We present an interactive system for creating
                 pen-and-ink-style line drawings from greyscale images in
                 which the strokes of the rendered illustration follow the
                 features of the original image. The user, via new
                 interaction techniques for editing a direction field,
                 specifies an orientation for each region of the image;
                 the computer draws oriented strokes, based on a
                 user-specified set of example strokes, that achieve the
                 same tone as the image via a new algorithm that compares
                 an adaptively-blurred version of the current illustration
                 to the target tone image. By aligning the direction field
                 with surface orientations of the objects in the image,
                 the user can create textures that appear attached to
                 those objects instead of merely conveying their
                 darkness. The result is a more compelling pen-and-ink
                 illustration than was previously possible from 2D
                 reference imagery.  }, 
    }
    @article{Schlechtweg:1997,
       author = {Stefan Schlechtweg},
       title = {Lines and How to Draw Them},
       volume = {},
       number = {},
       journal = {Norsk samarbeid inner grafisk databehandling},
       year = {February 1997},
       pages = {4--6}, 
       annote = {The drawing of lines on the computer has been an area of
                 interest for several years. In the beginning, there were
                 more practical reasons behind the development of line
                 drawing algorithms (as for instance the rasterization of
                 lines by BRESENHAM), later more esthetic reasons came
                 into play. This article gives an overview of techniques
                 for drawing lines with certain effects. A line in this
                 context is not necessarily a straight line but can be
                 every kind of curve. The presented methods are only three
                 examples of this interesting area: a simulation of real
                 brush-strokes, a vector-oriented technique for
                 2D-drawings and a method which can be applied to the
                 output of an analytical renderer to create illustrative
                 effects in line drawings.  },
    
    }
    
    @Unpublished{Smith97,
       author = "Alvy Ray Smith",
       title = "Digital {P}aint {S}ystems {H}istorical {O}verview",
       note = "Microsoft Corporation",
       month = may,
       year = "1997",
    
       annote = {This documentation is prepared in responce to the
                 solicitation of information on Digital Paint Systems by
                 the Subcommittee on May 2, 1997.
    
                 The period I will cover is from the late 1960's to the
                 early 1980s, from the beginings of the technology of
                 digital painting up to the first consumer products that
                 implemented it.  I include a little information about
                 major developments in the later 1980s.  Two surveys that
                 cover this later period fairly well-when the emergence fo
                 the perrsonal computer completly changed the software
                 universe--were both published in the magizine Computer
                 Graphics World [Smith82a, Robertson88].  My emphasis, of
                 course, is on those systems I knew firsthand.
    
                 I begin with a simple timeline of programs and systems.
                 I will attempt a weghting and a "genealogy" of these in a
                 later section, where I will also narrow the field to
                 those painting systems that have directly affected the
                 movie industry.},
    
    }
    
    @InProceedings{walt97,
      author =       "Bruce Walter and Gun Alppay and Eric P. F.
                     Lafortune and Sebastian Fernandez and Donald P.
                     Greenberg",
      title =        "Fitting {V}irtual {L}ights For {N}on-{D}iffuse {W}alkthroughs"
    ,
      booktitle =    "SIGGRAPH 97 Conference Proceedings",
      year =         "1997",
      month =        aug,
      pages =        {45-48}
    }
    
    @article{zhu_algo,
            Author   ={Ciyou Zhu and Richard H. Byrd and 
                       Peihuang Lu and Jorge Nocedal },
            Title    ={Algorithm 778: L-BFGS-B: Fortran subroutines for 
                       large-scale bound-constained optimization},
            journal = {ACM Trans. Math. Software},
            volume = {23},
            number = {4},
            Address  ={},
            pages = {550--560},
            Year     ={1997} 
    }
    
    
    
    @article{Tanaka:1997:PIE,
       author = {T. Tanaka and N. Ohnishi},
       title = {Painting-like Image Emphasis based on Human Vision Svstems},
       volume = {16},
       number = {3},
       journal = {Computer Graphics Forum},
       year = {August 1997},
       pages = {253--260},
       keywords = {image emphasis, display technique, visual processing, 
                   painting simulation, dynamic range compression},
       abstract = {Regional image emphasis is often evident in paintings
                   and illustrations. This technique increases local
                   contrast while reducing global contrast by amplifying
                   image intensity on shadowed surfaces, reducing
                   intensity on illuminated surfaces, and then expanding
                   contrast at intensity edges. The effects are assumed to
                   result from the visual processing needed to interpolate
                   the real world onto canvas. Therefore, we propose an
                   intensity emphasis method based on human vision. This
                   method simulates the adaptation of photoreceptor cells
                   and the lateral inhibition of receptive fields. These
                   attributes of a vision system are realized by
                   computation of relative intensity and differential
                   intensity in small areas. The proposed method can
                   successfully generate painting-like artifacts, which
                   greatly improves the perception of visual elements
                   displayed in an image. Since the method efficiently
                   reduces the dynamic range of images, it can be used for
                   displaying highlighted images on standard graphic
                   monitors. Experiments on a computer-generated image and
                   a photograph confirm the advantages of our
                   method. Proceedings of Eurographics '97.  }
    }
    
    @InProceedings{Treavett,
       author = "S. M. F. Treavett and M. Chen",
       title = "Statistical {T}echniques for the {A}utomated {S}ynthesis of
                      {N}on-{P}hotorealistic {I}mages",
       booktitle = "Proc. 15th Eurographics UK Conference",
       month = mar,
       year = "1997",
       annote = {In the field of computer graphics there is an increasing
                 demand for non-photorealistic effects.  Techniques have
                 been developed to this end but most involve substantial
                 runtime interaction form the user.  This paper presents a
                 new approach that uses statistical techniques to
                 automaticly and reproducibly generate non-photorealistic
                 images.  This automatic system could have far ranging
                 uses, including frame by frame conversion of video to
                 produce special effects.  Information from the source
                 image is obtained using statistical analysis techniques.
                 Statistical simulations are used to control the placement
                 of effects in the final image.  The paper includes a
                 number of example images produced by the system.},
    
    }
    
    @book{tuft97,
            author  = "Edward Tufte",
            title   = "Visual explanations",
            publisher   = "Graphics Press",
            city    =  "Cheshire, CT",
            year    = {1997}
    }
     
    @article{Wood:1997:MPF,
       author = {Daniel N. Wood and Adam Finkelstein and John F. Hughes
                 and Craig E. Thayer and David H. Salesin},
       title = {Multiperspective Panoramas for Cel Animation},
       journal = {Proceedings of SIGGRAPH 97},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1997},
       editor = {Turner Whitted},
       publisher = {Addison Wesley},
       pages = {243--250},
       note = {ISBN 0-89791-896-7. Held in Los Angeles, California.},
       keywords = {CGI production, compositing, illustration, image-based
                   rendering, mosaics, multiplaning, non-photorealistic
                   rendering},
       annote = {We describe a new approach for simulating apparent camera
                 motion through a 3D environment. The approach is
                 motivated by a traditional technique used in 2D cel
                 animation, in which a single background image, which we
                 call a multiperspective panorama,is used to incorporate
                 multiple views of a 3D environment as seen from along a
                 given camera path. When viewed through a small moving
                 window, the panorama produces the illusion of 3D
                 motion. In this paper, we explore how such panoramas can
                 be designed by computer, and we examine their application
                 to cel animation in particular. Multiperspective
                 panoramas should also be useful for any application in
                 which predefined camera moves are applied to 3D scenes,
                 including virtual reality fly-throughs, computer games,
                 and architectural walk-throughs. }, 
    }
    
    @InProceedings{zhang97,
     author = {H. Zhang and K. Hoff III},
      month = {April},
      year = 1997,
      title = {Fast Backface Culling Using Normal Masks},
      booktitle = {Proc. 1997 Symposium on Interactive 3D Graphics},
      pages = {103--106}
    }
    
    
    @article{Buchanan:1996:SEW,
       author = {John W. Buchanan},
       title = {Special Effects with Half-toning},
       volume = {15},
       number = {3},
       journal = {Computer Graphics Forum},
       year = {August 1996},
       editor = {Jarek Rossignac and Fran{\c{c}}ois X. Sillion},
       publisher = {Blackwell Publishers},
       pages = {97--108},
       note = {ISSN 1067-7055},
       keywords = {Half-toning, non-photorealistic rendering, graphic design},
       annote = {Half-toning is the process by which gray-scale images are
                 approximated with sets of black and white pixels. The
                 process works because our eyes perceive a local average,
                 thus half-toning seeks to approximate the local
                 average. Ideally this approximation should be
                 accomplished without introducing "undesirable"
                 artifacts. In many situations the stylized display of
                 images is desired. Often this stylized display is
                 accomplished by the addition of semi-structured
                 artifacts. In current applications the designer processes
                 the image using tools provided by some image processing
                 package. The resulting image is then half-toned and
                 printed. Half-toning these processed images can reduce
                 the visual impact of the special effects that have been
                 introduced in the image. In this paper we show that the
                 processes of controlled artifact introduction and
                 half-toning can successfully be combined. By combining
                 these two processes we ensure that the printed image is
                 what the designer intended. We present a brief overview
                 of the current error-diffusion half-toning techniques. We
                 then propose several ways in which artifacts can be
                 introduced to the image. This discussion is accompanied
                 by a set of illustrative images.  In particular, we
                 discuss the introduction of false edges and the
                 alteration of the scan pattern. We illustrate these
                 techniques with a variety of images. We conclude the
                 paper with a discussion on these new half-ioning methods
                 for the generation of binary gray-scale textures. In
                 addition to showing how to generate these binary
                 gray-scale textures we also show how these gray-scale
                 textures can be used to half-tone images. Proceedings of
                 Eurographics '96. }, 
    }
    
    
    @InProceedings{chi96*35,
      author =       "Jutta Schumann and Thomas Strothotte and Andreas Raab
                     and Stetan Laser",
      title =        "Assessing the Effect of {NonPhoto-realistic} Rendered
                     Images in {CAD}",
      pages =        "35--41",
      ISBN =         "0-201-94687-4",
      editor =       "Michael J. Tauber and Victoria Bellotti and Robin
                     Jeffries and Jock D. Mackinlay and Jakob Nielsen",
      booktitle =    "Proceedings of the Conference on Human Factors in
                     Computing Systems : Commun Ground",
      month =        apr # "~13--18",
      publisher =    "ACM Press",
      address =      "New York",
      year =         "1996",
      annote = {Recent work in computer graphics has resulted in new
                techniques for rendering so-called non-photorealistic
                images. While such features are now already appearing in
                commercially available software, little is known about the
                effect of non-photorealistic images on users and their
                usefulness in specific contexts.
    
                In this paper we report on an empirical study with 54
                architects who compared the output of a sketch-renderer
                for producing pencil-like drawings with standard output of
                CAD systems for architectural designs. The results show
                that the different kinds of renditions actually have a
                very different effect on viewers and that
                non-photorealistic images actually do deserve their place
                in the repertoire of CAD systems. },
    
    }
    
    @phdthesis{ Decaudin:1996:thesis,
       author = "Phillippe Decaudin",
       title = "{Modeling using Fusion of 3D Shapes for Computer Graphics 
                 -- Cartoon-Looking Rendering of 3D Scenes}",
       school = "Universite de Technologie de Compiegne",
       year = "1996",
       address = "France",
       month = {dec},
       note	= {}
    }
    
    @TechReport{ Decaudin:1996:CLR,
      author = "Phillippe Decaudin",
      title =  "Cartoon-Looking Rendering of 3D-Scenes",
      year =   "1996",
      month =  jun,
      number = "INRIA 2919",
      institution =  "Universite de Technologie de Compiegne",
      address ="France",
      abstract = "Cartoon-looking rendering of 3D scenes.  This rendering
                  technique produces images having the appearance of a
                  traditional cartoon from a 3D description of the scene
                  (a static or an animated scene).  
                  The 3D scene is rendered with techniques allowing to: 
                  - outline the profiles and edges of objects in back, 
                  - color uniformly the patches, 
                  - render shadows (self-shadows and projected-shadows) 
                    due to light sources. ", 
    }
    
    @phdthesis{elen96,
       author = "Elena Driskill",
       title = {Towards the Design, Analysis, and Illustration of Assemblies},
       school = "University of Utah",
       year = "1996",
       address = "Department of Computer Science, Salt Lake City, Utah",
       month = sep,
    
    
       abstract = {This document presents an integrate approach for
                   helping designers to specify, revise, analyze, and
                   illustrate assemblies of mechanical parts within the
                   context of a common data structure and set of assembly
                   features.  An implementation to test the validity of
                   these ideas has been integrated into an existing
                   spline-based geometric modeling system.
    
                   There were several distinct facets to this research
                   effort. Methodology for assembly planning was explored
                   to allow a user to lay out the assembly in a
                   diagrammatic form, before creating any geometry.  A
                   rough design, laid out initially, can gradually be
                   refined, and the individual components can be designed
                   and edited later using spline-based geometric modeling
                   operations. Research into assembly specification
                   examined how best to allow the user to describe the way
                   parts are actually connected together to form
                   subassemblies, and eventually the final product.  Also
                   considered were questions of part interference and part
                   removablility in order to help the user evaluate the
                   utility and manufacturability of the design.  Finally,
                   exploded view illustration was explored, with a view
                   toward enabling the user to create clear and
                   informative exploded views of the assembly with minimal
                   intervention.  Throughout, information obtained in
                   earlier stages of design was useful in helping to
                   automate later design steps.
    
                   During the course of this project the author developed
                   a representation of assembly convenient for handling
                   multiple assembly-related tasks, addressed the special
                   problems of interactive assembly design by introduction
                   new constructs for specifying assembly information,
                   explored the usefulness of interactive interference
                   detection techniques, and considered artistic issues,
                   such as good ways to arrange exploded parts in an
                   illustration, as part of creating a practical
                   application.}  
    }
    @article{Hoppe:1996:PM,
           author = {Hugues Hoppe},
           title = {Progressive Meshes},
           journal = {Proceedings of SIGGRAPH 96},
           series = {Computer Graphics Proceedings,
        Annual Conference Series},
           year = {1996},
           month = {August},
           editor = {Holly Rushmeier},
           publisher = {Addison Wesley},
           pages = {99--108},
           note = {ISBN 0-201-94800-1. Held in New
        Orleans, Louisiana.},
           annote = {Highly detailed geometric models are
        rapidly becoming commonplace in computer
        graphics. These models, often represented as
        complex triangle meshes, challenge rendering
        performance, transmission bandwidth, and storage
        capacities. This paper introduces the progressive
        mesh (PM) representation, a new scheme for
        storing and transmitting arbitrary triangle
        meshes. This efficient, lossless,
        continuous-resolution representation addresses
        several practical problems in graphics: smooth
        geomorphing of level-of-detail approximations,
        progressive transmission, mesh compression, and
        selective refinement. In addition, we present a
        new mesh simplification procedure for
        constructing a PM representation from an
        arbitrary mesh. The goal of this optimization
        procedure is to preserve not just the geometry of
        the original mesh, but more importantly its
        overall appearance as defined by its discrete and
        scalar appearance attributes such as material
        identifiers, color values, normals, and texture
        coordinates. We demonstrate construction of the
        PM representation and its applications using
        several practical models. },
        }
    
    @article{Interrante:1996:ITS,
            author = {Victoria Interrante and Henry Fuchs and Stephen
         Pizer},
            title = {Illustrating Transparent Surfaces with
         Curvature-Directed Strokes },
            journal = {IEEE Visualization '96},
            year = {1996},
            month = {October},
            editor = {Roni Yagel and Gregory M. Nielson},
            publisher = {IEEE},
            pages = {211--218},
            note = {ISBN 0-89791-864-9},
         }
    
    @Article{Lebaredian96,
       Author  = "Rev Lebaredian",
       Title   = "{Traditional Cel Animation Look with 3D Renderers}", 
       Journal= {Siggraph 96 Visual Proceedings, ACM SIGGRAPH, ACM Press},
       Year    = 1996,
       annote = {This sketch shows a combination of rendering and image
                 processing techniques that produce a cel animation look.
                 All of the following work was completely developed by me
                 with the exception of the trick edge detection and line
                 masking methods which I further developed from the work
                 of Guy Williams who is also affiliated with Warner
                 Brothers Digital Studio. },
    }
    
    @article{Meier:1996:PRF,
       author = {Barbara J. Meier},
       title = {Painterly Rendering for Animation},
       journal = {Proceedings of SIGGRAPH 96},
       year = {August 1996},
       pages = {477--484},
       annote = {We present a technique for rendering animations in a
                 painterly style.  The difficulty in using existing still
                 frame methods for animation is getting the paint to
                 "stick" to surfaces rather than randomly change with each
                 frame, while still retaining a hand-crafted look. We
                 extend the still frame method to animation by solving two
                 major specific problems of previous techniques. First our
                 method eliminates the "shower door" effect in which an
                 animation appears as if it were being viewed through
                 textured glass because brush strokes stick to the
                 viewplane not to the animating surfaces. Second, our
                 technique provides for frame-to-frame coherence in
                 animations so that the resulting frames do not randomly
                 change every frame. To maintain coherence, we model
                 surfaces as 3d particle sets which are rendered as 2d
                 paint brush strokes in screen space much like an artist
                 lays down brush strokes on a canvas. We use geometric and
                 lighting properties of the surfaces to control the
                 appearance of brush strokes. This powerful combination of
                 using 3d particles, surface lighting information, and
                 rendering 2d brush strokes in screen space gives us the
                 painterly style we desire and forces the brush strokes to
                 stick to animating surfaces. By varying lighting and
                 choosing brush stroke parameters we can create many
                 varied painterly styles. We illustrate the method with
                 images and animated sequences and present specific
                 technical and creative suggestions for achieving
                 different looks. }, 
    }
         
    @InProceedings{Salisbury:1996:SDR,
       author =   "Mike Salisbury and Corin Anderson and Dani Lischinski
                    and David H. Salesin",
       title =    {Scale-Dependent Reproduction of Pen-and-Ink Illustrations}, 
       series =   "Annual Conference Series",
       pages =    "461--468",
       booktitle =    "SIGGRAPH 96 Conference Proceedings",
       year =     "1996",
       organization = "ACM SIGGRAPH",
       publisher =    "Addison Wesley",
       month =    aug,
       note =     "held in New Orleans, Louisiana, 04-09 August 1996",
       annote = "This paper describes a representation for pen-and-ink
                 illustrations that allows the creation of high-fidelity
                 illustrations at any scale or resolution. We represent a
                 pen-and-ink illustration as a low-resolution grey-scale
                 image, augmented by a set of discontinuity segments,
                 along with a stroke texture. To render an illustration at
                 a particular scale, we first rescale the grey-scale image
                 to the desired size and then hatch the resulting image
                 with pen-and-ink strokes. The main technical contribution
                 of the paper is a new reconstruction algorithm that
                 magnifies the low-resolution image while keeping the
                 resulting image sharp along discontinuities.", }
    
    @Article{Schofield96,
        Author  = "Simon Schofield",
        Title   = "{Piranesi: A 3-D Paint System}", 
        Journal= {Eurographics UK 96 Conference Proceedings},
        Year    = 1996,
        Volume  = {},
        Number  = {},
        Month = {},
        pages = {} 
    } 
    
    @Article{Schumann96,
       Author  = "Jutta Schumann and Thomas Strothotte and Andreas Raab 
                   and Stefan Laser",
       Title   = "{Assessing the Effect of Non-Photorealistic Rendered 
                    Images in CAD}", 
       Journal= {CHI 96 Electronic Proceedings},
       Year    = 1996,
       Volume  = {},
       Number  = {},
       Month = {},
       pages = {}, 
       annote = {Recent work in computer graphics has resulted in new
                 techniques for rendering so-called non-photorealistic
                 images. While such features are now already appearing in
                 commercially available software, little is known about
                 the effect of non-photorealistic images on users and
                 their usefulness in specific contexts.
    
                 In this paper we report on an empirical study with 54
                 architects who compared the output of a sketch-renderer
                 for producing pencil-like drawings with standard output
                 of CAD systems for architectural designs. The results
                 show that the different kinds of renditions actually have
                 a very different effect on viewers and that
                 non-photorealistic images actually do deserve their place
                 in the repertoire of CAD systems.},
    } 
    
    @InProceedings{turk96,
        Author  = "Greg Turk and David Banks",
        Title   = "Image-Guided Streamline Placement", 
        Booktitle = {SIGGRAPH 96 Conference Proceedings },
        Year    = 1996,
        pages = {453-460}, 
        Month = aug, 
        annote = {Accurate control of streamline density is key to
                  producing several effective forms of visualization of
                  2-dimensional vector fields. We introduce a technique
                  that uses an energy function to guide the placement of
                  streamlines at a specified density. This energy function
                  uses a low-pass filtered version of the image to measure
                  the difference between the current image and the desired
                  visual density. We reduce the energy (and thereby
                  improve the placement of streamlines) by (1) changing
                  the positions and lengths of streamlines, (2) joining
                  streamlines that nearly abut, and (3) creating new
                  streamlines to fill sufficiently large gaps. The entire
                  process is iterated to produce streamlines that are
                  neither too crowded nor too sparse. The resulting
                  streamlines manifest a more hand-placed appearance than
                  do regularly- or randomly-placed streamlines. Arrows can
                  be added to the streamlines to disambiguate flow
                  direction, and flow magnitude can be represented by the
                  thickness, density, or intensity of the lines. },
    }
    
    @InProceedings{Winkenbach:1996:RPS,
       author =   "Georges Winkenbach and David H. Salesin",
       title =    "Rendering {P}arametric {S}urfaces in {P}en and {I}nk",
       editor =   "Holly Rushmeier",
       series =   "Annual Conference Series",
       pages =    "469--476",
       booktitle =    "SIGGRAPH 96 Conference Proceedings",
       year =     "1996",
       organization = "ACM SIGGRAPH",
       publisher =    "Addison Wesley",
       month =    aug,
       note =     "held in New Orleans, Louisiana, 04-09 August 1996",
       annote = "This paper presents new algorithms and techniques for
                 rendering parametric free-form surfaces in pen and ink.
                 In particular, we introduce the idea of
                 ``controlled-density hatching'' for conveying tone,
                 texture, and shape. The fine control over tone this
                 method provides allows the use of traditional texture
                 mapping techniques for specifying the tone of pen-and-ink
                 illustrations. We also show how a planar map, a data
                 structure central to our rendering algorithm, can be
                 constructed from parametric surfaces, and used for
                 clipping strokes and generating outlines.  Finally, we
                 show how curved shadows can be cast onto curved objects
                 for this style of illustration.", }
    
    @article{Zeleznik:1996:SAI,
       author = {Robert C. Zeleznik and Kenneth P. Herndon and John F. Hughes},
       title = {SKETCH: An Interface for Sketching 3D Scenes},
       journal = {Proceedings of SIGGRAPH 96},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {August 1996},
       editor = {Holly Rushmeier},
       publisher = {Addison Wesley},
       pages = {163--170},
       note = {ISBN 0-201-94800-1. Held in New Orleans, Louisiana.},
       annote = {Sketching communicates ideas rapidly through approximate
                 visual images with low overhead (pencil and paper), no
                 need for precision or specialized knowledge, and ease of
                 low-level correction and revision. In contrast, most 3D
                 computer modeling systems are good at generating
                 arbitrary views of precise 3D models and support
                 high-level editing and revision. The SKETCH application
                 described in this paper attempts to combine the
                 advantages of each in order to create an environment for
                 rapidly conceptualizing and editing approximate 3D
                 scenes. To achieve this, SKETCH uses simple
                 non-photorealistic rendering and a purely gestural
                 interface based on simplified line drawings of primitives
                 that allows all operations to be specified within the 3D
                 world. }, 
    }
    
    @techreport{elbe95,
       author   = "Gershon Elber",
       title   = "Gridless Halftoning of Freeform Surfaces via a
                  Coverage of Isoparametric Curves ",
       institution= "Center for Intelligent Systems Report",
       number  =  "9507",
       year   = "1995",
       address   = "Israel Institute of Technology",
       month   = mar,
       note   = {}
    }
     
    
    @Article{Lavallee:1995,
       author = "S. Lavallee and R. Szeliski and L. Brunie",
       title = "Anatomy-based registration of three-dimensional medial images, range images, X-ray projections, and three-dimensional models using octree-splines",
       journal = "Computer Integrated Surgery",
       year =  "1995",
       publisher =  "MIT Press",
       volume = "",
       number = "",
       pages = "115--143",
       month = {},
       note = "",
    
    }
    
    @techreport{HPPEX,
       author   = "Hewlette Packard",
       title   = "HP PEX Texture Mapping",
       institution= "www.hp.com/mhm/WhitePapers/PEXtureMapping/PEXtureMapping.html",
       number  =  "",
       year   = "2000",
       address   = "",
       month   = {},
       note   = {}
    }
    
    @Article{Elber:1995:LAR,
       author = "Gershon Elber",
       title = "Line art rendering via a coverage of isoparametric curves",
       journal = "IEEE Transactions on Visualization and Computer Graphics",
       year =  "1995",
       volume = "1",
       number = "3",
       pages = "231--239",
       month = sep,
       note = "ISSN 1077-2626",
    
    }
    
    @InProceedings{Fekete:1995:TPS,
       author =   "{Jean-Daniel} Fekete and {\'{E}}rick Bizouarn and
              {\'{E}}ric Cournarie and Thierry Galas and
              Fr{\'{e}}d{\'{e}}ric Taillefer",
       title =    "{TicTacToon}: {A} {P}aperless {S}ystem for {P}rofessional
              {2-D} Animation",
       editor =   "Robert Cook",
       series =   "Annual Conference Series",
       pages =    "79--90",
       booktitle =    "SIGGRAPH 95 Conference Proceedings",
       year =     "1995",
       organization = "ACM SIGGRAPH",
       publisher =    "Addison Wesley",
       month =    aug,
       note =     "held in Los Angeles, California, 06-11 August 1995",
       keywords =     "2D animation, vector-based sketching, cel animation",
       annote = "TicTacToon is a system for professional 2D animation
                 studios that replaces the traditional paper-based
                 production process. TicTacToon is the first animation
                 systemto use vector-based sketching and painting: it uses
                 an original method to transform a pen trajectory with
                 varying pressure into a stroke of varying thickness, in
                 real-time. TicTacToon provides resolution independence, a
                 virtually infinite number of layers, the ability to
                 dynamically manage perspective and sophisticated support
                 for reuse of drawings. Other innovations include
                 replacement of the rostrum model with a 3D model and
                 integration into the overall 2D animation production
                 process. TicTacToon is in daily use by 2D animation
                 studios for a wide range of productions, from commercials
                 to television series and even a feature film. The user
                 interface enables professionals to sketch and draw as
                 they do on paper.  Over 100 professional animators have
                 used the system over a period of two years and most need
                 less than an hour before beginning productive
                 work. TicTacToon eliminates most tedious tasks and frees
                 professional animators for more creative work.",
    
    }
    
    @Article{Guo,
    author = "Qinglian Guo",
    journal = "IEEE Trans. Fundamentals",
    title = "Generating {R}ealistic {C}alligraphy {W}ords",
    volume = "E78-A",
    number = "11",
    month = nov,
    year = "1995",
    pages = "1556--1558"
    }
    
    
    @article{Hall:1995:NSC,
       author = {P. Hall},
       title = {Non-Photorealistic Shape Cues for Visualization },
       journal = {Winter School of Computer Graphics 1995},
       year = {February 1995},
       note = {Held in held at University of West Bohemia, Plzen, 
           Czech Republic, 14-18 February 1995.},
    }
    
    @book{Jain:1995,
       author = {Ramesh Jain and Rangachar Kasturi and Brian Schunck},
       title = {Machine Vision},
       year = {1995},
       publisher = {McGraw-Hill},
       pages = {52--61},
    }
    
     
    
    @Article{Kruger:1995,
    author = "Antonio Kruger and Thomas Rist",
    journal = "Electronic Proceedings of the ACM Workshop on Effect Abstractions in Mulitmedia",
    title = "Since Less is often More: Methods for Stylistic Abstractions in 3D-Graphics", 
    number = "4",
    month = nov,
    year = "1995", 
    }
    
    @article{Interrante:1995:ETS,
            author = {Victoria Interrante and Henry Fuchs and Stephen
         Pizer},
            title = {Enhancing Transparent Skin Surfaces with Ridge and Valley Lines },
            journal = {IEEE Visualization '95},
            year = {1995},
            month = {October},
            editor = {},
            publisher = {IEEE},
            pages = {221--228},
            note = { },
         }
    
    @Article{Lansdown:1995:ERR,
      author =   "John Lansdown and Simon Schofield",
      title =    "Expressive {R}endering: {A} {R}eview of {N}onphotorealistic
             {T}echniques",
      journal =      "IEEE Computer Graphics and Applications",
      year =     "1995",
      volume =   "15",
      number =   "3",
      pages =    "29--37",
      month =    may,
    }
    
    @book{macm95,
            editor  = "Tom Ruppel",
            title   = "The way science works",
            publisher	= "MacMillan",
            year    = 1995,
    	volume	= 1,
    	address	= {},
    	edition	= {},
    	month	= {},
    	note	= {}
    }
    
    @article{Ostromoukhov:1995:AS,
       author = {Victor Ostromoukhov and Roger D. Hersch},
       title = {Artistic Screening},
       journal = {Proceedings of SIGGRAPH 95},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {1995},
       month = {August},
       editor = {Robert Cook},
       publisher = {Addison Wesley},
       pages = {219--228},
       note = {ISBN 0-201-84776-0. Held in Los Angeles, California.},
       keywords = {Image reproduction, graphic design, halftoning, artistic
                   screening, microlettering},
       annote = {Artistic screening is a new image reproduction technique
                 incorporating freely created artistic screen elements for
                 generating halftones. Fixed predefined dot contours
                 associated with given intensity levels determine the
                 screen dot shape's growing behavior. Screen dot contours
                 associated with each intensity level are obtained by
                 interpolation between the fixed predefined dot
                 contours. A user-defined mapping transforms screen
                 elements from screen element definition space to screen
                 element rendition space. This mapping can be tuned to
                 produce various effects such as dilatations, contractions
                 and non-linear deformations of the screen element
                 grid. Discrete screen elements associated with all
                 desired intensity levels are obtained by rasterizing the
                 interpolated screen dot shapes in the screen element
                 rendition space. Since both the image to be reproduced
                 and the screen shapes can be designed independently, the
                 design freedom offered to artists is very great. The
                 interaction between the image to be reproduced and the
                 screen shapes enables the creation of graphic designs of
                 high artistic quality.  Artistic screening is
                 particularly well suited for the reproduction of images
                 on large posters. When looked at from a short distance,
                 the poster's screening layer may deliver its own
                 message. Furthermore, thanks to artistic screening, both
                 full size and microscopic letters can be incorporated
                 into the image reproduction process. In order to avoid
                 counterfeiting, banknotes may comprise grayscale images
                 with intensity levels produced by microletters of varying
                 size and shape. },
    }
    
    
    
    
    @article{Perlin:1995:LPP,
      author = {Ken Perlin and Luiz Velho},
      title = {Live Paint: Painting With Procedural Multiscale Textures},
      journal = {Proceedings of SIGGRAPH 95},
      year = {August 1995},
      pages = {153--160},
      annote = {We present actively procedural multiresolution paint
            textures. Texture elements may be linearly combined to
            create complex composite textures that continue to refine
            themselves when viewed at successively greater
            magnification. Actively procedural textures constitute a
            powerful drawing tool that can be used in a
            multiresolution paint system. They provide a mechanism to
            generate an infinite amount of detail with a simple and
            compact representation. We give several examples of
            procedural textures and show how to create different
            painting effects with them. }, 
    }
    
     
    @TechReport{Smith:1995,
      author = "Alvy Ray Smith",
      title =  "Varieties of Digital Painting",
      year =   "1995",
      month =  "August",
      pages =  "1--10",
      keywords =     "image, moment, paint, art, artistic ",
      institution =  "Microsoft Research",
      abstract = "The purpose of this memo is to distinguish between the
          various meanings that digital painting may have.  It is
          important to have a taxonomy so that intelligent
          conversation may proceed on such important issues as
          multi resolution paint programs.  Each type of painting
          will be discussed in its multi resolution
          generalization.  The taxonomy here splits painting into
          discrete and continuous categories and each of those
          into maxing and non-maxing sub categories.",
      annote = " The interesting thing about this paper is the fact that
             by using a scale invariant primitive for a brush stroke
             continuous (i.e. multi resolution) paintings could be
             made.  None of the other automatic painting programs,
             with the possible exception of Curtis, have achieved
             this.", 
    }
    
    
    @article{Wang:1995:VS,
      author = {Sidney W. Wang and Arie E. Kaufman},
      title = {Volume Sculpting },
      journal = {1995 Symposium on Interactive 3D Graphics},
      year = {1995},
      month = {April},
      editor = {Pat Hanrahan and Jim Winget},
      publisher = {ACM SIGGRAPH},
      pages = {151--156},
      note = {ISBN 0-89791-736-7},
    }
    
    
    @article{Wong:1995:HWS,
      author = {Tien-tsin Wong},
      title = {Halftoning with Selective Precipitation and Adaptive Clustering},
      journal = {Graphics Gems V},
      year = {1995},
      editor = {Alan W. Paeth},
      publisher = {Academic Press},
      pages = {302--313},
      note = {ISBN 0-12-543455-3. Held in Boston.},
      keywords = {Image Processing},
      annote = {includes code },}
    
    
    @article{Banks:1994,
           author = {David C. Banks},
           title = {Illumination in Diverse Codimensions},
           journal = {Proceedings of SIGGRAPH 94},
           year = {1994},
           pages = {327-334},
          
    }
     
    @article{Berman:1994:MPA,
           author = {Deborah F. Berman and Jason T. Bartell 
             and David H. Salesin},
           title = {Multiresolution Painting and Compositing},
           journal = {Proceedings of SIGGRAPH 94},
           year = {1994},
           pages = {85--90},
           keywords = {compositing, infinite-resolution, 
               multiresolution images, painting, wavelets, zooming},
           annote = {We describe a representation for multiresolution
             images - images that have different resolutions
             in different places - and methods for creating
             such images using painting and compositing
             operations. These methods are very easy to
             implement, and they are efficient in both memory
             and speed.  Only the detail present at a
             particular resolution is stored, and the most
             common painting operations, "over" and "erase,"
             require time proportional only to the number of
             pixels displayed. We also show how
             fractional-level zooming can be implemented in
             order to allow a user to display and edit
             portions of a multiresolution image at any
             arbitrary size. },
    }
    
    @book{brow94,
            author  = "Tom Browning",
            title   = "Timeless techniques for better oil paintings",
            publisher	= "North Light Books",
            year    = 1994,
    	volume	= {},
    	address	= {New York},
    	edition	= {},
    	month	= {},
    	note	= {}
    }
    
    @article{Finkelstein:1994:MC,
       author = {Adam Finkelstein and David H. Salesin},
       title = {Multiresolution Curves},
       journal = {Proceedings of SIGGRAPH 94},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {1994},
       month = {July},
       editor = {Andrew Glassner},
       publisher = {ACM Press},
       pages = {261--268},
       note = {ISBN 0-89791-667-0. Held in Orlando, Florida.},
       keywords = {curve compression, curve editing, curve fitting, curve
                   smoothing, direct manipulation, scan conversion,
                   wavelets},
       annote = {We describe a multiresolution curve representation, based
                 on wavelets, that conveniently supports a variety of
                 operations: smoothing a curve; editing the overall form
                 of a curve while preserving its details; and
                 approximating a curve within any given error tolerance
                 for scan conversion. We present methods to support
                 continuous levels of smoothing as well as direct
                 manipulation of an arbitrary portion of the curve; the
                 control points, as well as the discrete nature of the
                 underlying hierarchical representation, can be hidden
                 from the user. The multiresolution representation
                 requires no extra storage beyond that of the original
                 control points, and the algorithms using the
                 representation are both simple and fast. },
    
    
    }
    
    @article{Hsu:1994:DAA,
       author = {Siu Chi Hsu and Irene H. H. Lee},
       title = {Drawing and Animation Using Skeletal Strokes},
       journal = {Proceedings of SIGGRAPH 94},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {July 1994},
       editor = {Andrew Glassner},
       publisher = {ACM Press},
       pages = {109--118},
       note = {ISBN 0-89791-667-0. Held in Orlando, Florida.},
       keywords = {Non-photorealistic rendering, stylish strokes, skeletal
           strokes, vector graphics, deformation, psuedo-3D model,
           animation, fractals},
       annote = {The use of skeletal strokes is a new vector graphics
             realization of the brush and stroke metaphor using
             arbitrary pictures as "ink." It is based on an idealized
             2D deformation model defined by an arbitrary path. Its
             expressiveness as a general brush stroke replacement and
             efficiency for interactive use make it suitable as a
             basic drawing primitive in drawing programs as well as
             windowing and page description systems. This paper
             presents our drawing and animation system, "Skeletal
             Draw," based on skeletal strokes. The effectiveness of
             the system in stylish picture creation is illustrated
             with various pictures made with it. Decisions made in the
             handling of sub-strokes in a higher order stroke and
             recursive strokes are discussed. The general anchoring
             mechanism in the skeletal stroke framework allows any
             arbitrary picture deformation to be abstracted into a
             single stroke. Its extension to piecewise continuous
             anchoring and the anchoring of shear angle and stroke
             width are explained. We demonstrated how this mechanism
             allows us to build up powerful pseudo-3D models which are
             particularly useful in the production of 2½ D cartoon
             drawings and animation. Animation sequences have been
             made to illustrate the ideas, including a vector graphics
             based motion blurring technique. }, 
    }
    
    @article{Miller:1994:EAF,
       author = {Gavin Miller},
       title = {Efficient Algorithms for Local and Global Accessibility Shading},
       journal = {Proceedings of SIGGRAPH 94},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {1994},
       month = {July},
       editor = {Andrew Glassner},
       publisher = {ACM Press},
       pages = {319--326},
       note = {ISBN 0-89791-667-0. Held in Orlando, Florida.},
       keywords = {Surface accessibility shading, visualisation, aging},
       annote = {This paper discusses the use of two different approaches
                 for computing the "accessibility" of a surface. These
                 metrics characterize how easily a surface may be touched
                 by a spherical probe. The paper also presents various
                 acceleration techniques for accessibility. The idea of
                 surface accessibility is extended to include "global
                 accessibility" which measures the ability of a spherical
                 probe to enter a structure from outside as well as to fit
                 locally on the surface. The visual effect of shading
                 using accessibility is shown to resemble the patina on
                 certain tarnished surfaces which have then been
                 cleaned. },
    }
    
    @article{Paeth:1994:ITF,
      author = {Alan W. Paeth},
      title = {Ideal Tiles for Shading and Halftoning },
      journal = {Graphics Gems IV},
      year = {1994},
      editor = {Paul S. Heckbert},
      publisher = {Academic Press},
      pages = {486--492},
      note = {ISBN 0-12-336155-9. Held in Boston.},
      keywords = {Image Processing},
    }
    
    @InProceedings{pnueli94,
        Author  = "Yachin Pnueli and Alfred M. Bruckstein",
        Title   = "Digdurer - a digital engraving system", 
        Booktitle = {The Visual Computer},
        volume = 10,
        pages = {277--292},
        Year    = 1994,
        Month = aug 
    }
    
    @Article{Pudet94,
      Author  = "Thierry Pudet",
      Title   = "Real Time Fitting of Hand-Sketched Pressure Brushstrokes", 
      Journal = {Eurographics 1994},
      volume = 13,
      number = 3,
      pages = {277--292},
      Year    = 1994,
      Month = aug,
      annote = {A method is described for fitting the outline of
            hand-sketched pressure brushstrokes with Bezier curves.
            It combines the brush-trajectory model, in which a stroke
            is generated by dragging a brush along a given trajectory,
            with a fast curve fitting algorithim.
    
            The method has been implemented for a vector-based drawing
            program in which the user draws with a cordless
            pressure-sensitive stylus on a digitizing tablet.  From
            the trajectory followed by the stylus, its associated
            pressure data, and a specified brush, a stroke of varible
            witdth is computed and displayed in real time.
    
            First, the digitized trajectory is fitted, thus removing
            noise.  Then, from polygonal approximations of the fitted
            trajectory and the brush outline, a polygonal
            approximaiton of the stroke outline is computed.  Working
            with polygonal approximations reduces the computations to
            simple geometric operations and greatly simplifies the
            treatmetn of dynamic, pressure-controlled brushes.  Last,
            the polygonal approximations of the stroke outline is
            fitted.  The result is a closed piecewise Bezier curve
            approximating the brushstroke outline to within and
            arbitrary error tolerance. },
    
    
    }
    
    @article{Robertson:1994:DT,
        author = {Barbara Robertson},
        title = {Digital Toons},
        journal = {Computer Graphics World},
        month   = jun,
        year = {1994},
        pages = {40--46},
        editor = {},
        keywords = {},
    }
    @article{Robertson:1994:DLC,
        author = {Barbara Robertson},
        title = {Disney Lets CAPS Out of the Bag},
        journal = {Computer Graphics World},
        month   = jul,
        year = {1994},
        pages = {58--64},
        editor = {},
        keywords = {},
    }
    
    @article{Salisbury:1994:IPI,
       author = {Michael P. Salisbury and Sean E. Anderson and Ronen
             Barzel and David H.  Salesin},
       title = {Interactive Pen-And-Ink Illustration},
       journal = {Proceedings of SIGGRAPH 94},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {July 1994},
       editor = {Andrew Glassner},
       publisher = {ACM Press},
       pages = {101--108},
       note = {ISBN 0-89791-667-0. Held in Orlando, Florida.},
       keywords = {Comprehensible rendering, non-photorealistic rendering,
           prioritized stroke textures},
       annote = {We present an interactive system for creating pen-and-ink
             illustrations. The system uses stroke textures -
             collections of strokes arranged in different patterns -
             to generate texture and tone. The user "paints" with a
             desired stroke texture to achieve a desired tone, and the
             computer draws all of the individual strokes. \\ The
             system includes support for using scanned or rendered
             images for reference to provide the user with guides for
             outline and tone. By following these guides closely, the
             illustration system can be used for interactive digital
             halftoning, in which stroke textures are applied to
             convey details that would otherwise be lost in this
             black-and-white medium. \\ By removing the burden of
             placing individual strokes from the user, the
             illustration system makes it possible to create fine
             stroke work with a purely mouse-based interface. Thus,
             this approach holds promise for bringing high-quality
             black-and-white illustration to the world of personal
             computing and desktop publishing. }, 
    }
    
    @phdthesis{Schofield94,
       author   = "Simon Schofield",
       title   = "{Non-photorealistic Rendering}",
       school   = "Middlesex University",
       year   = "1994",
       address   = "England",
       month   = {},
       note   = {}
    }
    
    @Article{Strothotte:1994:HRF,
      author =   "T. Strothotte and B. Preim and A. Raab and J. Schumann
                  and D. R. Forsey",
      title =    "How to Render Frames and Influence People",
      journal =      "Com{\-}pu{\-}ter Graphics Forum",
      volume =   "13",
      number =   "3",
      pages =    "C/455--C/466",
      year =     "1994",
      coden =    "CGFODY",
      ISSN =     "0167-7055",
      bibdate =      "Mon Apr 14 10:23:20 MDT 1997",
      conflocation = "Oslo, Norway; 12-16 Sept. 1994",
      conftitle =    "15th Annual Conference and Exhibition. EUROGRAPHICS'94",
      corpsource =   "Dept. of Simulation and Graphics, Otto-von-Guericke
                      Univ. of Magdeburg, Germany",
      keywords = "architectural CAD; architectural design; Architectural
                  design; architectural drawings; Architectural drawings;
                  architectural drawings; CAD; frame rendering; Frame
                  rendering; hand-down images; Hand-down images; hand-down
                  images; human factors; human-computer interaction;
                  Human-computer interaction; information flow;
                  Information flow; line styles; Line styles; objective
                  process; Objective process; primitives; Primitives;
                  primitives; prototypical; Prototypical renderer;
                  renderer; rendering (computer graphics); rendering
                  plants; Rendering plants; rendering plants; rendering
                  shadows; Rendering shadows; rendering systems; Rendering
                  systems; rendering systems; subjective processes;
                  Subjective processes; theoretical framework; Theoretical
                  framework; theoretical framework; user interfaces",
      thesaurus =  "Architectural CAD; Human factors; Rendering [computer
                    graphics]; User interfaces",
       annote = { Rendering systems generally treat the production of
                  images as an objective process governed by the laws of
                  physics.  However, perception and understanding on the
                  part of viewers are subjective processes influnced by a
                  variety of factors.  For example, in the presentation of
                  architectural drawings, the apparent precesion with
                  which the drawings are made will affect whethe the
                  viewer considers the design as part of a preliminary
                  desigh or as part of a final polished project, and to
                  some extent the level of confidence the viewer has in
                  the encoded information.
    
                  In this paper we develop techniques for rendering images
                  in a way that differs from the usual photorealistic or
                  wire-frame output of renderers.  In particular, our
                  techniques allow a user to adjust the rendering of a
                  scene to produce images using primitives with varible
                  degrees of precision, from approximations that resemble
                  vague "five-minute-sketches" to more mature but still
                  hand-drawn images.  We provide a theoretical framework
                  for analysing the information flow from the computer to
                  the user via such images.  Finally, we describe the
                  design and implementation of a prototypical renderer and
                  show examples of its output.}, 
    }
    
    @article{Winkenbach:1994:CPI,
       author = {Georges Winkenbach and David H. Salesin},
       title = {Computer-Generated Pen-And-Ink Illustration},
       journal = {Proceedings of SIGGRAPH 94},
       series = {Computer Graphics Proceedings, Annual Conference Series},
       year = {July 1994},
       editor = {Andrew Glassner},
       publisher = {ACM Press},
       pages = {91--100},
       note = {ISBN 0-89791-667-0. Held in Orlando, Florida.},
       keywords = {architectural rendering, comprehensible rendering,
           non-photorealistic rendering, prioritized stroke
           textures, resolution-dependent rendering, texture
           indication},
       annote = {This paper describes the principles of traditional
             pen-and-ink illustration, and shows how a great number of
             them can be implemented as part of an automated rendering
             system. It introduces "stroke textures," which can be
             used for achieving both texture and tone with line
             drawing. Stroke textures also allow resolution-dependent
             rendering, in which the choice of strokes used in an
             illustration is appropriately tied to the resolution of
             the target medium. We demonstrate pthese techniques using
             complex architectural models, including Frank Lloyd
             Wright's "Robie House." }, 
    }
    
    
    @InProceedings{Cabral:1993:IVF,
       author = "Brian Cabral and Leith (Casey) Leedom",
       title = {Imaging Vector Fields Using Line Integral Convolution},
       booktitle = "Computer Graphics (SIGGRAPH '93 Proceedings)",
       year = "1993",
       editor = "James T. Kajiya",
       pages = "263--272",
       month = aug,
       volume = "27",
       keywords = "Picture/Image generation, Three-Dimensional Graphics
           and Realism, Enhancement, convolution, filtering,
           rendering, visualization, texture synthesis, flow
           fields, special effects, periodic motion filtering",
       annote = "Imaging vector fields has applications in science, art,
             image processing and special effects. An effective new
             approach is to use linear and curvilinear filtering
             techniques to locally blur textures along a vector
             field. This approach builds on several previous texture
             generation and filtering techniques. It is, however,
             unique because it is local, one-dimensional and
             independent of any predefined geometry or texture. The
             technique is general and capable of imaging arbitrary
             two- and three-dimensional vector fields. The local
             one-dimensional nature of the algorithm lends itself to
             highly parallel and efficient implementations.
             Furthermore, the curvilinear filter is capable of
             rendering detail on very intricate vector fields.
             Combining this technique with other rendering and image
             processing techniques - like periodic motion filtering -
             results in richly informative and striking images.  The
             technique can also produce novel special effects.",
         }
    
    @InProceedings{ Rossignac:1992,
       author = "J. Rossignac and M. van Emmerik",
       title = "Hidden contours on a frame-buffer",
       booktitle = "Proceedings of the 7th Eurographics Workshop on 
            Computer Graphics Hardware",
       address = "Cambridge, UK",
       publisher = "",
       year= "September 1992",
       pages = "188--204",
       abstract="To comply with drafting practices and because shaded
             images do not always reveal the internal or hidden
             structures of 3D models, designers need wireframe images
             with hidden lines dashed and noncontour tessellation
             edges removed.  Software techniques for wireframe
             rendering of polyhedra that require the
             viewpoint-dependent identification of the visible
             portions of intersection and contour (i.e. silhouette)
             edges are too slow for interactive applications.
             Hardware support in contemporary graphics pipelines is
             unavailable or at best limited to the identification of
             contour edges.  In this paper, new hardware assisted
             techniques for hidden-line removal and determination of
             contour edges are presented.  The techniques do not
             require any face/edge adjacency information can can be
             implement easily on any platform that supports a hardware
             z-buffer.",
    
    }
    
    @InProceedings{Cockshott:a,
    author = "Tunde Cockshott and John Patterson and David England",
    title = "Modelling the {T}exture of {P}aint",
    pages = "217--226",
    booktitle = "Computer Graphics Forum",
    volume = "11",
    year = "1992",
    editor = "A. Kilgour and L. Kjelldahl",
    conference = "EUROGRAPHICS '92",
    keywords = "simulation, electronic paint system, bump mapping,
              interaction, parallelism"
    }
    
    @InProceedings{Cockshott:b,
    author = "Tunde Cockshott and David England",
    title = "Wet and Sticky: Supporting Interaction with Wet Paint",
    pages = "199--208",
    booktitle = "People and Computers VI: Proceedings of the HCI '91 Conference",
    year = "1991",
    editor = "D. Diaper and H. Hammond",
    keywords = "paint modeling and systems, novel interaction, parallelism"
    }
    
    @phdThesis{Cockshott:1991,
      author = "Tunde Cockshott",
      title =  "Wet and Sticky: A Novel Model for Computer-Based Painting",
      year =   "1991",
      keywords =     "image, rendering, paint, artistic, brush",
      school =  "University of Glasgow",
      xurl =   "",
      abstract = "The problems of computer based painting are considered from 
          a fine arts stand point.  A detailed criticism of existing 
          approaches is provided.  This criticism centers on the limited 
          depth of existing models and the resultant limited complexity 
          and relative poverty of their mark making capabilities.  
          The notion of the importance of the accidental in art is 
          highlighted and an argument is made of its inclusion in computer 
          based painting models.  An informal task analysis is carried 
          out and a description is provided for the task of domain 
          modeling.  The results of this task analysis confirm the 
          inadequacy of the existing computer based painting models.  
    
          A novel paradigm, Wet & Sticky, is proposed which models 
          the physical and behavioral characteristics of paint rather 
          that just its color properties.  The initial proposals for the 
          model require that it mimics the actions of gravity and the 
          effects of aging of different types of paint.  An experimental 
          development procedure is used to produce and refine a set of 
          algorithms for and implementation of the new model.  This new 
          model is capable of supporting the production of marks which 
          possess a greater degree of complexity than possible with 
          existing models.  Throughout the development of the model the 
          aim is to balance the requirements of producing a convincing 
          visual and behavioral simulation.  The new model also provides 
          the opportunity for new tools and techniques which are not only 
          unsupportable with existing systems but also with traditional 
          fine art painting methods.   A selection of photographic 
          results are included which provide support for the accuracy of 
          the behavior of the model. ", 
    
      annote = " This thesis presents a good method for simulating painting on a 
             computer.  The model includes canvas or substrate, 
             paint (with parameters beyond color), gravity, and diffusion.  
             Both the method of approaching the problem, and the software 
             engineering are sound.  Many improvements could be made, 
             and his system could now run in real time.",
    }
    
    
    @article{Guo:1991:MTD,
        author = {Qinglian Guo and T. L. Kunii},
        title = {Modeling the diffuse painting of sumie },
        journal = {IFIP Modeling in Computer Graphics},
        year = {1991},
        editor = {T. L. Kunii},
        keywords = {paint brush},
    }
    
    @book{lamb91,
            author  = "Patricia Lambert",
            title   = "Controlling color: a practical introduction for
                      designers and artists",
            publisher       = "Everbest Printing Company Ltd.",
            year    = 1991,
            volume  = 1,
            address = {},
            edition = {},
            month   = {},
            note    = {}
    }
    
    
    
    @InProceedings{haeb90,
            Author  = "Paul Haeberli",
            Title   = "Paint {B}y {N}umbers: {A}bstract {I}mage {R}epresentation", 
            Booktitle = {SIGGRAPH 90 Conference Proceedings },
            Year    = 1990,
            Month = aug 
    }
    
    
    @Article{haeb90b,
            Author  = "Paul Haeberli",
            Title   = "{T}he {A}ccumulation {B}uffer: {H}ardware {S}upport
                      for {H}igh-{Q}uality {R}endering", 
            Journal= {SIGGRAPH 90 Conference Proceedings},
            Year    = 1990,
            Volume  = 24,
            Number  = 3,
            Month = aug 
    }
    
    @article{Litwinowicz:1991:IA2,
       author = {Peter C. Litwinowicz},
       title = {Inkwell: A 2 ½-D animation system},
       volume = {25 },
       number = {4},
       journal = {Computer Graphics (Proceedings of SIGGRAPH 91)},
       year = {July 1991},
       editor = {Thomas W. Sederberg},
       pages = {113--122},
       note = {ISBN 0-201-56291-X. Held in Las Vegas, Nevada.},
       keywords = {animation, character animation, free form deformation},
       abstract="Inkwell, an experimental 2 ½-D keyframe animation
                 system, is the subject of this paper.  Inkwell provides
                 an intuitive user interface for creating and animating
                 diagrams, graphs and charts, and simple characters and
                 cartoons.  Inkwell also has a patch primitive that
                 facilitates deformations and animation of textured
                 regions.  The system provides editing features that
                 include shape and timing control as well as digital
                 filtering of parameters.  Finally, Inkwell has
                 deformation primitives that enable an animator to warp
                 geometry in an intuitive manner. Inkwell was used to
                 produce Pigment Promenade, a computer animated short
                 shown at SIGGRAPH 1990.",
    } 
    
    @article{Schumacher:1991:ACO,
      author = {Dale A. Schumacher},
      title = {A Comparison of Digital Halftoning Techniques},
      journal = {Graphics Gems II},
      year = {1991},
      editor = {James Arvo},
      publisher = {Academic Press},
      pages = {57--71, 502-508},
      note = {ISBN 0-12-064481-9. Held in Boston.},
      keywords = {Image Processing},
      annote = {includes code },
    }
    
    
    @Article{Velho91,
        Author  = "Luiz Velho and Jonas de Miranda Gomes",
        Title   = "{Digital Halftoning with Space Filling Curves}", 
        Journal= {Computer Graphics (Proc. Siggraph), ACM SIGGRAPH, ACM Press},
        Year    = 1991,
        Volume  = {25},
        Number  = {4},
        Month = {},
        pages = {81-90} 
    }
    
    @Article{Pham:1991:EBS,
      author = "Binh Pham",
      title = "Expressive brush strokes",
      journal = "Computer Vision, Graphics, and Image Processing.
                 Graphical Models and Image Processing",
      volume =   "53",
      number =   "1",
      pages =    "1--6",
      month =    jan,
      year =     "1991",
      keywords = "3D; Animation process; Bristle; Computation task;
                  Expressive brush strokes; Spatial position coordinates;
                  Uniform cubic B-splines; Variable offset approximation",
      thesaurus =    "Computer animation; Splines [mathematics]",
      abstract = "Expressive brush strokes are modeled using a technique
                  based on variable offset approximation of uniform cubic
                  B-splines.  The trajectory of a brush stroke is
                  represented as a 3D cubic B-spline and each bristle as a
                  3D offset cubic B-spline of this trajectory.  The first
                  two coordinates are the spatial position coordinates and
                  the third coordinate represents the shade of each
                  bristle.  This technique facilitates the process of
                  inputting data, simplifies the computation task, and
                  provides some advantages in the animation process of
                  brush strokes. ",
      annote = "This paper presents some incremental changes is Strassmann's 
                paper, offset curves are used instead of a pixel array. ",
    }
    
    
    @article{Seligmann:1991:AGO,
       author = {Dor{\'{e}}e Duncan Seligmann and Steven Feiner},
       title = {Automated generation of intent-based 3D illustrations},
       volume = {25 },
       number = {4},
       journal = {Computer Graphics (Proceedings of SIGGRAPH 91)},
       year = {July 1991},
       editor = {Thomas W. Sederberg},
       pages = {123--132},
       note = {ISBN 0-201-56291-X. Held in Las Vegas, Nevada.},
       keywords = {illustrations, automated picture generation, 
                   knowledge-based graphics, non-photorealistic rendering},
       abstract = "This paper describes an automated intent-based approach
                   to illustration.  An illustration is a picture that is
                   designed to fulfill a communicative intent such as
                   showing the location of an object or showing how an
                   object is manipulated.  An illustration is generated by
                   implementing a set of stylistic decisions, ranging from
                   determining the way in which an individual object is
                   lit, to deciding the general composition of the
                   illustration.  The design of an illustration is treaded
                   as goal-driven process within a system of constraints.
                   The goal is to achieve communicative intent; the
                   constraints of the illustration techniques an
                   illustration can apply.
    
                   We have developed IBIS (Intent-based illustration
                   system), a system that puts these ideas into practice.
                   IBIS designs illustrations using a generate-and-test
                   approach, relying upon a rule-based system of methods
                   and evaluators.  Methods are rules that specify how to
                   accomplish visual effects, while evaluators are rules
                   that specify how to determine how well a visual effect
                   is accomplished in an illustration.  Examples of
                   illustrations designed by IBIS are included.", 
    }
    
    @article{Small:1991:SWB,
      author = {David Small},
      title = {Simulating Watercolor by Modeling Diffusion, Pigment, 
           and Paper Fibers },
      journal = {Proceedings of SPIE '91},
      year = {February 1991},
      keywords = {paint brush},
    
      abstract = "This paper explores a parallel approch to the problem of
          predicting the actions of pigment and water when applied
          to paper fibers.  This work was done on the Connection
          Machine II, whose parallel architecture allows one to
          cast the problem as that of a complex cellular automata.
          One defines simple rules for the behavior of each cell
          based on the state of that cell and its immdeiate
          neighbors.  By repeating the computation for each cell
          in the paper over many time steps, elaborate and
          realistic behaviors can be achieved.  The simulation
          takes into account diffusion, surface tension, gravity,
          humidity, paperabsorbency, and the molecular weight of
          each pigment.  At each time step a processor associated
          with each fiber in the paper computes water and pigment
          gradients, surface tension and gravitational forces, and
          decides if there should be any moven=mento of material.
          Pigment and water can be applied and removed (blotting)
          with masks created form typr or scanned images.  Use of
          a parallel processor simplifies the creation and testing
          of software, and varibles can be stored and manipulated
          at haigh precision.  The resulting simulation runs at
          approximately one-tenth real time. ",
    }
    
    @article{will91,
       Author  = "Lance Williams",
       Title   = "Shading in {T}wo {D}imensions", 
       journal =  "Graphics Interface '91",
       year    = 1991,
       pages   = {143-151},
       month   = {},
       note    = {}
    } 
    
    @article{dool90,
       Author  = "Debra Dooley and Michael F. Cohen ",
       Title   = {Automatic Illustration of 3D Geometric Models: Surfaces}, 
       journal =  "IEEE Computer Graphics and Applications",
       year    = 1990,
       volume  = 13,
       number  = 2,
       pages   = {307-314},
       month   = {},
       abstract = { Computer-generated models are becoming increasingly
            complex in structure, and therefore more difficult to
            display within single concise images.  To better
            convey to the view overall shape information about the
            model, the advantages of line drawings and shaded
            surface renderings need to be used cooperatively.  A
            system based on the techniques of traditional
            illustrators is described for automatically generating
            illustrations of complex three dimensional models.
            The system relies upon a richer set of display
            primitives, which are also outlined.  Algorithmic
            details for emphasizing significant model components
            are discussed, and some preliminary results are
            presented.}  }
    
    @InProceedings{Elber:1990:HCR,
       author = "Gershon Elber and Elaine Cohen",
       title = "Hidden {C}urve {R}emoval for {F}ree {F}orm {S}urfaces",
       pages = "95--104",
       booktitle =  "Computer Graphics (SIGGRAPH '90 Proceedings)",
       volume = "24",
       year = "1990",
       month = aug,
       editor = "Forest Baskett",
       conference = "held in Dallas, Texas; 6-10 August 1990",
       keywords = "hiddent curve removal, curve-curve intersection,
           visibility propagation",
       abstract = "This paper describes a hidden curve algorithm
           specifically designed for sculptured surfaces.  A
           technique is described to extract the visible curves
           for a given scene without the need to approximate the
           surface by polygons.  This algorithm produces higher
           quality results and polygon based algorithms, as most
           of the output set has an exact representation.  Surface
           coherence is used to speed up the process.  Although
           designed for sculptured surfaces, this algorithm is
           also suitable for polygonal data.",
    }
    
    @article{Haeberli:1990:PBN,
       author = {Paul E. Haeberli},
       title = {Paint By Numbers: Abstract Image Representations},
       volume = {24 },
       number = {4},
       journal = {Proceedings of SIGGRAPH 90},
       year = {August 1990},
       pages = {207--214},
       keywords = {painting, image processing, abstract images},
       annote = "{Computer graphics research has concentrated on creating
          photo-realistic images fo synthetic objects.  These
          images communicate surface shading and curvature, as
          well as the depth relaionships of objects in a scene.
          These renderings are tradionally represented by a
          rectangular array of pixels that tile the image plane.
    
          As an alternative to photo-realism, it is possible to
          create abstract images using and ordered collection of
          brush strokes.  These abstract images filter and refine
          visual information before is is presented to the viewer.
          By controlling the color, shape, size, and orentation of
          individual brush strokes, impressionistic paiontings co
          computer generated of photographic images can easily be
          created.}",
    
    }
    
    @InProceedings{Hanrahan:1990:DWP,
       author =   "Pat Hanrahan and Paul E. Haeberli",
       title =    "Direct {WYSIWYG} {P}ainting and {T}exturing on 3{D}
          {S}hapes",
       pages =    "215--223",
       booktitle =    "Computer Graphics (SIGGRAPH '90 Proceedings)",
       volume =   "24",
       year =     "1990",
       month =    aug,
       editor =   "Forest Baskett",
       conference =   "held in Dallas, Texas; 6-10 August 1990",
       keywords =     "painting, direct manipulation, user-interface",
       annote = "{This paper describes a 3D object-space paint program.
          This program allows the user to directly manipulate the
          parameters used to shade the surface of the 3D shape by
          applying pigment to its surface.  The pigment has all
          the properties normally associated with material shading
          models.  This includes, but is not limited to, the
          diffuse color, the specular color, and the surface
          roughness.  The pigment can also have thickness, which
          is modeled by simultaneously creating a bumb map
          attached to the shape.  The output of the paint program
          is a 3D model with associated texture maps.  This
          information can be used with any rendering program with
          texture mapping capabilities.  Almost all traditional
          techniques of 2D cocmputer image painting have analogues
          in 3D object painting, but there are also many new
          techniques unique to 3D.  One example is the use of
          solid textures to patteren the surface.}",
    
    
         }
    
    @InProceedings{Saito:1990:CRD,
       author = "Takafumi Saito and Tokiichiro Takahashi",
       title = "{C}omprehensible {R}endering of 3-{D} {S}hapes",
       pages = "197--206",
       booktitle =  "Computer Graphics (SIGGRAPH '90 Proceedings)",
       volume = "24",
       year = "1990",
       month = aug, 
       conference = "held in Dallas, Texas; 6-10 August 1990",
       keywords = "comprehensible rendering, visualization, geometric
           property, contour lines, edge enhancement, line drawing
           illustrations, topographical maps, medical imaging,
           surface analysis",
       abstract = "We propose a new rendering technique that produces 3-D
           images with enhanced visual comprehensibility.  Shape
           features can be readily understood if certain geometric
           properties are enhanced.  To achieve this, we develop
           drawing algorithms for discontinuities, edges, contour
           lines, and curved hatching.  Al of them are realized
           with 2-D image processing operations instead of line
           tracking processes, so that they can be efficiently
           combined with conventional surface rendering
           algorithms.
    
           Data about the geometric properties of the surfaces are
           preserved as Geometric Buffers (G-buffers).  Each
           G-Buffer contains one geometric property such as the
           depth or the normal vector of each pixel.  By using
           G-buffers as intermediate results, artificial
           enhancement processes are separated from geometric
           processes (projection and hidden line removal) and
           physical process (shading and texture mapping), and
           performed as postprocesses.  This permits a user to
           rapidly examine various combinations of enhancement
           techniques without excess recomputation, and easily
           obtain the most comprehensible image.
    
           Our method can be widely applied for various purposes.
           Several of these, edge enhancement, line drawing
           illustrations, topographical maps, medical images, and
           surface analysis, are presented in this paper.", }
    
    
    @Article{Williams:1990:P,
      author =   "Lance Williams",
      title =    "{3D} Paint",
      journal = {1990 Symposium on Interactive 3D Graphics},
      pages =    "225--233",
      year =     "1990",
      abstract = "This paper advances a means by which the conventions and 
           method of digital painting and image manipulation programs 
           can be extended into the third dimension, providing sculpting 
           tools that are natural and appropriate for a restricted byt 
           very useful class of models. ", 
    
      annote = "This paper provides a method of merging painting and sculpting 
            by using the raster field as a height field. ",
    
    
    
    }
    
    @book{edwa89,
            author  = "Betty Edwards",
            title   = "Drawing on the Right Side of the Brain",
            publisher   = "Jeremy P. Tarcher/Putnam",
            city    =  "New York, NY",
            year    = {1989}
    }
     
    @book{mart89,
            author  = "Judy Martin",
            title   = "Technical illustration: materials, methods, and techniques",
            publisher	= "Macdonald and Co Publishers",
            year    = 1989,
    	volume	= 1,
    	address	= {},
    	edition	= {},
    	month	= {},
    	note	= {}
    }
    
    @article{Vermeulen:1989:PA,
      author = {Allan H. Vermeulen and Peter P. Tanner},
      title = {PencilSketch -- A pencil-based paint system },
      journal = {Graphics Interface '89},
      year = {1989},
      month = {June},
      pages = {138--143},
    }
    
    @Book{Mantyla:ISM88,
      author =       "Marrti Mantyla",
      title =        "An Introduction to Solid Modelingg",
      publisher =    "Computer Science Press",
      year =         "1988",
      ISBN =         "0-88175-108-1",
    }
    
    @Article{ware88,
        Author ="Colin Ware",
        Title  = "Color {S}equences for {U}nivariate {M}aps: {T}heory,
        {E}xperiments, and {P}rinciples",
        Journal="IEEE Computer Graphics \& Applications",
        Year   = 1988,
        Volume = 8,
        Number = 5,
        Pages  = {41-49} }
    
    @article{Kamada:1987:AET,
       author = {Tomihisa Kamada and Satoru Kawai},
       title = {An Enhanced Treatment of Hidden Lines},
       volume = {6 },
       number = {4},
       journal = {ACM Transactions on Graphics},
       year = {1987},
       month = {October},
       pages = {308--323},
    }
    
    
    @Book{Ulichney:DH87,
      author =       "Robert Ulichney",
      title =        "Digital Halftoning",
      publisher =    "The MIT Press",
      pages =        "xiv + 362",
      year =         "1987",
      ISBN =         "0-262-21009-6",
    }
    
    @Article{Strassmann:1986,
      author =   "Steve Strassmann",
      title =    "Hairy Brushes",
      journal =      "Siggraph",
      volume =   "20",
      number =   "4",
      pages =    "225--232",
      month =    Aug,
      year =     "1986",
      abstract = "Paint brushes are modeled as a collection of bristles which 
          evolve over the course of the stroke, leaving a realistic image 
          of a sumi brush stroke.  The major representational units are 
          (1) Brush: a compound object composed of bristles, 
          (2) Stroke: a trajectory of position and pressure, 
          (3) Dip: a description of the application of paint to a 
               class of brushes,
          (4) Paper: a mapping onto the display device.  
          This modular system allows experimentation with various 
          stochastic models of ink flow and color change.  By selecting 
          from a library of brushes, dips, and papers, the stroke can 
          take on a wide variety of expressive textures. ", 
      annote = "This paper presents one of the first ideas for modeling brushes 
            and ink.  The brushes are modeled by an array of pixels, and 
            the brush stroke by a cubic b-spline, in order to render the 
            stroke the pixel array is dragged along the spline curve. By 
            varying pixel parameters during the brush stroke a user is able
            to simulate stroke shading, and dry brush effects. ",
    
    }
    
    @book{Preparata:1985,
       author = {F. P. Preparata and M. I. Shamos},
       title = {Computational Geometry},
       year = {1985},
       address	= {New York},
       publisher = {Springer-Verlag},
       pages = {},
    }
    
    
    @article{Lewis:1984:TSF,
       author = {John-Peter Lewis},
       title = {Texture synthesis for digital painting},
       volume = {18 },
       number = {3},
       journal = {Computer Graphics (Proceedings of SIGGRAPH 84)},
       year = {July 1984},
       editor = {Hank Christiansen},
       pages = {245--252},
       note = {Held in Minneapolis, Minnesota.},
       keywords = {Paint System, Texture Generation},
       abstract = "{The problem of digital painting is considered from a
            signal processing viewpoint, and is reconsidered as a
            problem of directed texture synthesis.  It is an
            important characteristic of natural texture that
            detail may be evident at many scales, and the detail
            at each scale may have distinct characteristics.  A
            "sparse convolution" procedure for generating random
            textures with arbitrary spectral content is described.
            The capability of specifying the textrue spectrum (and
            thus the amount of detail at each scale) is an
            improvement over stocastic texture synthesis processes
            which are scalebound or which have a prescribed 1/f
            spectrum.  This spectral texture synthesis procedure
            provides the basis for a digital paint system which
            rivals the textrual sophistication of traditional
            artistic media.  Applications in terrain synthesis and
            textruing computer rendered objects are also shown.}",
    }
    @article{Smith:1984:PFA,
            author = {Alvy Ray Smith},
            title = {Plants, Fractals and Formal Languages},
            volume = {18},
            number = {3},
            journal = {Computer Graphics (Proceedings of SIGGRAPH 84)},
            year = {1984},
            month = {July},
            editor = {Hank Christiansen},
            pages = {1--10},
            note = {Held in Minneapolis, Minnesota.},
            keywords = {model stochastic plant, Fractals, Pattern Generation},
            annote = {Graftals. Methods for displaying natural objects 
                      based on formal  models are presented. 
                      In particular, deterministic
                      models are shown to exhibit sufficient variety to be used in
                      production graphic systems. },
     }
     
    @article{Whitted:1983:ALD,
       author = {T. Whitted},
       title = {Anti-Aliased Line Drawing Using Brush Extrusion},
       volume = {17 },
       number = {},
       journal = {Computer Graphics},
       year = {July 1983},
       pages = {151--156},
       note = {Held in USA.},
       keywords = {line drawings and antialiasing and brush extrusion},
       abstract = "{This algorithim draws lines on a gray-scale raster
            display by dragging a "brush" along the path of the
            line.  The style fot eh line is determined by the
            properties fo the brush.  An anti-aliasing calculation
            is performed once for the brush itself and therafter
            only a trivial additional operation is needed for each
            pixel through which the brush is dragged to yeild an
            anti-aliased line.
    
            There are few constraints on the size, shape and
            attributes of the brush.  Lines can be curved as well
            as straight.  It is possible to produce lines with a
            three dimentional appearance.}",
    
        }
    
    @article{Williams:1983:PP,
            author = {Lance Williams},
            title = {Pyramidal Parametrics},
            volume = {17 },
            number = {3},
            journal = {Computer Graphics (Proceedings of SIGGRAPH 83)},
            year = {1983},
            month = {July},
            pages = {1--11},
            note = {Held in Detroit, Michigan.},
            keywords = {texture mapping, antialiasing},
         }
    
    @Book{Foley:1982:FOI,
      author = {J. D. Foley and A. van Dam},
      title = {Fundamentals of Interactive Computer Graphics },
      year = {1982},
      publisher = {Addison-Wesley},
    }
    
    
    @InCollection{Smith82,
    author = "Alvy Ray Smith",
    title = "Paint",
    pages = "501--515",
    editor = "Beatty and Booth",
    publisher = "IEEE Computer Society Press",
    year = "1982",
    edition = "Second",
    booktitle = "IEEE Tutorial on Computer Graphics"
    }
    
    @Book{gold80,
            Author   ={E. Bruce Goldstein},
            Title    ={Sensation and perception},
            Publisher={Wadsworth Publishing Co.},
            Address  ={Belmont, California},
            Year     ={1980} }
    
    
    @article{Appel:1979:THL,
      author = {A. Appel and F. J. Rohlf and A. J. Stein},
      title = {The haloed line effect for hidden line elimination},
      volume = {13 },
      number = {3},
      journal = {Computer Graphics (Proceedings of SIGGRAPH 79)},
      year = {1979},
      month = {August},
      pages = {151--157},
      note = {Held in Chicago, Illinois.},
      keywords = {algorithmic aspects, hidden line/surface removal},
    }
    
    @Article{Franke79,
        Author ="Franke,  R.",
        Title  = "A Critical Comparison of Some Methods for Interpolation of Scattered Data",
        Journal= "Naval Postgraduate School",
        Year   = 1979,
        Number = {Report NPS-53-79-003}, 
    }
    @article{Crow:1977:SAF,
            author = {Franklin C. Crow},
            title = {Shadow Algorithms for Computer Graphics},
            volume = {11 },
            number = {2},
            journal = {Computer Graphics (Proceedings of SIGGRAPH 77)},
            year = {1977},
            month = {July},
            editor = {James George},
            pages = {242--248},
            note = {Held in San Jose, California.},
            keywords = {shadow},
         }
    
    @Book{Johnson1997,
      author =       "Crockett Johnson",
      title =        "Harold and the Purple Crayon",
      publisher =    "Harper-Collins Juvenile Books",
      year =         "1977",
    }
    
    @book{birr76,
            author  = "Faber Birren",
            title   = "Color perception in art",
            publisher	= "Van Nostrand Reinhold Company",
            year    = 1976,
    	volume	= {},
    	address	= {New York},
    	edition	= {},
    	month	= {},
    	note	= {}
    }
    
    @Article{phon75,
        Author ="Bui-Tuong Phong",
        Title  = "{I}llumination for {C}omputer {G}enerated {I}mages",
        Journal= "Communications of the ACM",
        Year   = 1975,
        Month = "June",
        Volume = 18,
        Number = 6,
        Pages  = {311-317} }
    
    @article{Appel:1967:TNO,
            author = {Arthur Appel},
            title = {The Notion of Quantitative Invisibility and the Machine
         Rendering of Solids },
            journal = {Proc. ACM Natl. Mtg.},
            year = {1967},
            publisher = {Thompson Books},
            pages = {387},
            note = {Held in Washington, DC.},
            keywords = {hidden line},
         }
    
    @InProceedings{Sutherland:163:SAM,
       author = "Ivan Sutherland",
       title = {Sketchpad: A Man-Machine Graphical Communication System},
       booktitle = "Proc. AFIPS Spring Joint Computer Conference",
       address = "Washington, D.C",
       publisher = "Spartan Books",
       year= "1963",
       pages = "329--346",
       abstract="The Sketchpad system makes it possible for a man and a
             computer to converse rapidly through the medium of lines
             drawings.  Heretofore, most interaction between man and
             computers has been slowed down by the need to reduce all
             communications to written statements that can be typed;
             in the past, we have been writing letters to rather than
             conferring with our computers. For many types of
             communication, such as describing the shape of a
             mechanical part or the connections of an electrical
             circuit, typed statements can prove cumbersome.  The
             Sketchpad system, by eliminating typed statements (except
             for legends) in favor of line drawings, opens up a new
             area of man-machine communication.",
    
    }
    
    @article{Hough,
            author = {P.V.C. Hough},
            title = {A method and means for recognizing complex patterens},
            journal = {U.S. Patent 3,069,654},
            year = {1962},
    }
    
    
    @Article{Gombrich,
        Author  = "E. Gombrich ",
        Title   = "{Formula and Experience}", 
        Journal= {Art and Illusion},
        address ={Phaidon, London},
        Year    = 1960,
        Volume  = {},
        Number  = {},
        Month = {},
        pages = {} 
    }
    
    
    ## perception
      
    @article{tjan95,
      Author  = "Bosco S. Tjan and Wendy L. Braje and Gordon
    		  E. Legge and Daniel Kersten",
      Title   = "Human Efficiency for Recognizing 3-{D} Objects in
    		  Luminance Noise", 
    	journal =  "Vision Research",
    	year    = 1995,
    	volume  = 35,
    	number  = 21,
    	pages   = {3053-3069},
    	month   = {},
    	note    = {}
    } 
    
      
    @article{braj95,
      Author  = "Wendy L. Braje and Bosco S. Tjan and  Gordon
    		  E. Legge ",
      Title   = "Human Efficiency for Recognizing and
    		  Detecting Low-pass Filtered Objects", 
    	journal =  "Vision Research",
    	year    = 1995,
    	volume  = 35,
    	number  = 21,
    	pages   = {2955-2966},
    	month   = {},
    	note    = {}
    } 
    
      
    
    @article{bied88,
      Author  = "Irving Biederman and Ginny Ju ",
      Title   = "Surface versus Edge-Based Determinants of
    		  Visual Recognition", 
    	journal =  "Cognitive Psychology",
    	year    = 1988,
    	volume  = 20,
    	pages   = {38-64},
    	month   = {},
    	note    = {}
    } 
    
      
    
    @article{chri96,
      Author  = "Chris Christou and Jan J. Koenderink and Andrea
    		  J. van Doorn",
      Title   = "Surface  Gradients, Contours and the
    		  Perception of Surface Attitude in Images of
    		  Complex Scenes", 
    	journal =  "Perception",
    	year    = 1996,
    	volume  = 25,
    	pages   = {701-713},
    	month   = {},
    	note    = {}
    } 
    
    
    @article{chris96,
      Author  = { Chris Christou and Jan J. Koenderink and Andrea
    		  J. van Doorn },
      Title   = { Surface gradients, contours and the perception of
    		  surface attitude in images of complex scenes }, 
    	journal =  "Perception",
    	year    = 1996,
    	volume  = 25,
    	number  = {},
    	pages   = "701-713",
    	month   = {},
    	note    = {}
    } 
    
    @article{Baeck69,
           author = {R. Baecker},
           title = {Picture Driven Animation},
           journal = {Interactive Computer Graphics},
           series = {Conference Proceedings, Spring Joint Computer Conference},
           year = {1969},
           month = {},
           editor = {Herbert Freeman},
           publisher = {IEEE Computer Society},
           pages = {},
           note = {},
    }
     
    @article{Burt71,
      Author  = {N. Burtnyk and M. Wein },
      Title   = { Computer-Generated Key Frame Animation }, 
    	journal =  "J. Society Motion Picture and Television Engineers",
    	year    = 1971,
    	volume  = 80,
    	number  = {3},
    	pages   = "149-153",
    	month   = {},
    	note    = {}
    } 
    
    @book{Catmull83,
      Author  = {E. Catmull },
      Title   = { Tween Users' Manual }, 
      publisher = {CGL Inc.},
      address ={New York},
    	journal =  "",
    	year    = 1983,
    	month   = {},
    	note    = {}
    } 
    
    @book{Camhy97,
      Author  = {S.W. Camhy},
      Title = {Art of the Pencil: A Revolutionary Look at Drawing,
                     Painting, and the Pencil.},
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ISBN = {0-8230-1373-1},
      year    = 1997,
    } 
    
    @book{Lewis84,
      Author  = {D. Lewis},
      Title   = {Pencil Drawing Techniques.}, 
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ISBN = {0-8230-3991-9},
      year    = 1984,
    }
    
    @book{Price93,
      Author  = {G. Price},
      Title   = {Pencil Drawing (fromthe Art is... Video Series)}, 
      publisher = {Crystal Productions},
      SBN = {1-56290-077-3},
      year    = 1993,
    }
    
    @book{Salwey25,
      Author  = {J. Salwey},
      Title   = {The Art of Drawing in Lead Pencil.}, 
      publisher = {B.T. Batsford, Ltd.},
      address ={London},
      year    = 1925,
    }
    
    @book{Watson78,
      Author  = {E.W. Watson},
      Title   = {Course in Pencil Sketching, Four Books in One.}, 
      publisher = {Van Nostrand Reinhold Company},
      address ={New York},
      ISBN = {0-442-29230-9},
      year    = 1978,
    }
    
    @book{Guptill77,
      Author  = {A.L. Guptill},
      Title   = {Rendering in Pencil.}, 
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ISBN = {0-8230-4531-5},
      year    = 1997,
    }
    
    @book{Franks88,
      Author  = {G. Franks},
      Title   = {Pencil Drawing.}, 
      publisher = {Walter Foster publishing Inc.},
      address ={Laguna Hills, CA},
      ISBN = {0-929261-03-8},
      year    = 1988,
    }
    
    @book{Douglas93,
      Author  = {D. Douglas and D. van Wyk},
      Title   = {The Drawing Process: Rendering.}, 
      publisher = {Prentice Hall, Inc.},
      ISBN = {0-13-219833-9},
      year    = 1993,
    }
    
    @book{Horton94,
      Author  = {J. Horton},
      Title   = {An Introduction to Drawing.}, 
      publisher = {Dorley Kindersley Limited},
      address ={London, England},
      ISBN = {0-13-123902-3},
      year    = 1994,
    }
    
    @book{Misawa93,
      Author  = {H. Misawa},
      Title   = {An introduction to Pencil Techniques: Easy Start Guide.}, 
      publisher = {Books Nippan},
      ISBN = {4766107144},
      year    = 1993,
    }
    
    @book{PET97,
      Author  = {Parramon Editorial Team},
      Title   = {Barron's Art handbooks Drawing.}, 
      publisher = {Barron's Educational Series, Inc.},
      address ={New York},
      ISBN = {0-7641-5007-3},
      year    = 1997,
    }
    
    @book{Jamieson86,
      Author  = {I. Hutton-Jamieson},
      Title   = {Colored Pencil Drawing Techniques.}, 
      publisher = {North Light Books},
      ASIN = {0891341471},
      year    = 1986,
    }
    
    @book{Martin97,
      Author  = {Judy Martin},
      Title   = {The Encyclopedia of Colored Pencil Techniques.}, 
      publisher = {Running Press},
      ISBN = {0762401176},
      year    = 1997,
    }
    
    @book{Lohan78,
      Author  = {Frank Lohan},
      Title   = {Pen and Ink Techniques.}, 
      publisher = {Contemporary Books, Inc.},
      address ={Chicago},
      ISBN = {0809274388},
      year    = 1978,
    }
    
    
    
    @book{Pitz57,
      Author  = {Henry C. Pitz},
      Title   = {Ink Drawing Techniques.}, 
      publisher = {Watson-Guptill Publications},
      address ={New York},
      year    = 1957,
    }
    
    
    @book{Simmons92,
      Author  = {Gary Simmons},
      Title   = {The Technical Pen.}, 
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ISBN = {0823052273},
      year    = 1992,
    }
    
    @book{Sato84,
      Author  = {S. Sato},
      Title   = {The Art of Sumi-e.}, 
      publisher = {Kodansha International},
      address ={Tokyo},
      ISBN = {0870115707},
      year    =1984,
    }
    
    @book{Dobie86,
      Author  = {Jeanne Dobie},
      Title   = {Making Color Sing.},
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ISBN = {0823029921},
      year    =1986,
    }
    
    @book{Rankin86,
      Author  = {Don Rankin},
      Title   = {Mastering Glazing Techniques in Watercolor.}, 
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ASIN = {0823030245},
      year    =1986,
    }
    
    @book{Szabo74,
      Author  = {Zoltan Szabo},
      Title   = {Creative Watercolor Techniques.}, 
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ASIN = {0823011194},
      year    =1974,
    }
    
    @book{Smith87,
      Author  = {Ray Smith},
      Title   = {The Artist's Handbook}, 
      publisher = {Alfred A. Knopf},
      ISBN = {0394555856},
      year    =1987,
    }
    
    @book{Callen82,
      Author  = {Athea Callen},
      Title   = {Techniques of the Impressionists}, 
      ISBN = {0890095450},
      year    =1982,
    }
    
    @book{Katchen90,
      Author  = {Carole Katchen},
      Title   = {Creative Painting with Pastel}, 
      publisher = {North Light Books},
      ISBN = {0891347895 },
      year    =1990,
    }
    
    @book{Kreutz86,
      Author  = {Gregg Kreutz},
      Title   = {Problem Solving for Oil Paintiers}, 
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ISBN = {0823040976},
      year    =1986,
    }
    
    @book{Schaeffer91,
      Author  = {S. Allyn Schaeffer},
      Title   = {The Big Book of Painting Nature in Oil}, 
      publisher = {Watson-Guptill Publications},
      address ={New York},
      ISBN = {0823005038},
      year    =1991,
    }
    
    @book{Thomas81,
      Author  = {Frank Thomas and Ollie Johnston},
      Title   = {Disney Animation -- The Illusion of Life.}, 
      publisher = {Abbeville Press},
      ASIN = {0896592332},
      year    =1981,
    }
    
    
    @book{Ivins88,
      Author  = {W.M. Ivins, Jr.},
      Title   = {How Prints Look}, 
      publisher = {John Murray Pupl.},
      address ={London},
      ISBN = {0807066478},
      year    =1988,
    }
    
    
    @book{Brunner84,
      Author  = {F. Brunner},
      Title   = {A Handbook of Graphic Reproduction Process}, 
      publisher = {Hasting House Publ.},
      address ={New York},
      year    =1984,
    }
    
    
    @book{Mukundan98,
            Author  = {R. Mukundan and K. R. Ramakrishnan},
            Title   = {Moment Functions in Image Analysis - Theory and Applications}, 
             publisher = {World Scientific Pub Co.},
            ISBN = {981-02-3524-0},
      year    =1998,
    }
    
    
    
    @book{Johnson77,
            Author  = {Crockett Johnson},
            Title   = {Harold and the Purple Crayon}, 
            publisher = {Harper-Collins Juvenile Books},
            ISBN =  {0064430227},
      year    =1977,
    }
    
    @book{martin89,
            Author  = {Judy Martin},
            Title   = {Technical Illustration: Materials, Methods, and Techniques}, 
            publisher = {MacDonald and Co. Publishers},
      year    =1989,
    }
    
    @book{Solso99,
            Author  = {Robert L. Solso},
            Title   = {Cognition and the Visual Arts}, 
            publisher = {MIT Press/Bradford Books},
            ISBN = {0262691868},
      year    =1999,
    }
    
    @book{Seuss71,
            Author  = {Dr. Seuss (Theodor Geisel)},
            Title   = {The Lorax}, 
            publisher = {Random House},
            address ={New york},
            ISBN = {0394823370},
      year    =1971,
    }
    
    @book{Seuss88,
            Author  = {Dr. Seuss (Theodor Geisel)},
            Title   = {The Foot Book}, 
            publisher = {Random House},
            address ={New york},
            ISBN = {0394809378},
      year    =1988,
    }
    
    
    @book{Tomas:TI:68,
      Author    = {T.A. Thomas},
      Title     = {Technical Illustration, 2nd. Edition}, 
      publisher = {McGraw-Hill},
      address   = {New York},
      ISBN      = {},
      year      = 1968,
    }
    
    
    @book{Giesecke36,
      Author    = {F. Giesecke and A. Mitchell and H. Spencer},
      Title     = {Technical Drawing}, 
      publisher = {The Macmillan Co.},
      address   = {New York},
      ISBN      = {},
      year      = 1936,
    }
    
    
    @book{Martin:89:HTI,
      Author    = {Judy Martin},
      Title     = {High Tech Illustration}, 
      publisher = {North Light Books},
      address   = {Cincinnati, OH},
      ISBN      = {},
      year      = 1989,
    }
    
    @book{Magnan70,
      Author    = {G.Magnan},
      Title     = {Using Technical Art: An Industry Guide}, 
      publisher = {John Wiley and Sons, Inc.},
      ASIN      = {0471563358 },
      year      = 1970,
    }
    
    @book{Hodges89,
      Author    = {Elaine Hodges, ed.},
      Title     = {The Guide Handbook of Scientific Illustration}, 
      publisher = {Van Nostrand Reinhold},
      address   = {New York},
      ISBN      = {},
      year      = 1989,
    }
    
    @book{Guptill76,
      Author    = {Arthur L. Guptill},
      Title     = {Rendering in Pen and Ink.}, 
      publisher = {Watson-Guptill Publications},
      address   = {New York},
      ISBN      = {0823045293},
      year      = 1976,
    }
    
    @book{Sullivan22,
      Author    = {Edmund J. Sullivan},
      Title     = {Line: an Art Study}, 
      publisher = {Chapman and Hall},
      address   = {},
      ISBN      = {},
      year      = 1922,
    }
    
    @Book{stro97,
      Author    = {Christine Strothotte and Thomas Strothotte},
      Title     = {Seeing Between the Pixels: Pictures in Interactive Systems},
      Publisher = {Springer-Verlag},
      Address   = {Berlin},
      Year      = {1997} 
    }
    
    @book{Lohan93,
      Author  = {Frank Lohan},
      Title   = {The Drawing Handbook}, 
      publisher = {Contemporary Books, Inc.},
      address ={Chicago},
      ISBN = {},
      year    = 1978,
    }
    
    @book{Evans96,
      Author    = {L. Evans},
      Title     = {The New Complete Illustration Guide: The Ultimate Trace 
                   File for Architects, Designers, Artists, and Students}, 
      publisher = {Van Nostrand Reinhold},
      address   = {New York},
      ISBN      = {},
      year      = 1996,
    }