mccool@csri.toronto.edu (Michael McCool) (11/15/89)
RE: 64 shades of grey is enough I really should qualify my earlier posting. What I stated was an opinion, based on experience. This experience has included certian kind of images that never showed an artifact. This is not my center of interest/research, so... consider this a preemptive self-flame. However, I think my point about adapting the colour map to the image is valid, although probability would probably not be the best measure (for instance, a black background would crowd most shades towards black, where discrimination is low). Some weighted function of probability and discrimination ability, combined with the gamma of the monitor, should give an artifact-free image. I suspect there would be pathological cases, but do these really justify the extra bandwidth needed for 256-level grey-scale?