http://news.povray.org/povray.binaries.images/thread/%3C42ff61ca%241%40news.povray.org%3E/
https://www.youtube.com/watch?v=oACegp4iGi0
https://github.com/ssingal05/ImageTransformer
Looks like in addition to processing images, it could be useful for generating
pigment patterns. (see @ 2:05)
