bastwood.com has a good page on images found in sound starting with the demon face in Aphex Twin’s “Windowlicker”. It turns out the demon is really an inverted version of the Twin himself. The site goes on to discuss how to find such images and how to create sound from images using common software.
There are some uses for image/video sonnification tools other than putting surprises in tunes. See the The vOICE synthetic vision software site which sells systems for the visually impaired.
Thanks to Alex for the link.