Image 1 (MC Integration, 16 random samples):

Image 2 (MC Integration, 16 stratified samples):

Image 3 (MC Integration, 100 random samples):

Image 4 (MC Integration, 100 stratified samples):

Image 5 (MC Integration, 100 random samples, bspline filter):

Image 6 (Density Estimation, 100 random samples per pixel on average):

Image 7 (Density Estimation, 100 stratified samples per pixel on average):

Image 8 (Metropolis, 100 samples per pixel on average: