Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!csri.toronto.edu!mccool
From: mccool@csri.toronto.edu (Michael McCool)
Newsgroups: comp.graphics
Subject: Colours and Grey Scale
Message-ID: <1989Nov14.110609.26840@jarvis.csri.toronto.edu>
Date: 14 Nov 89 16:06:09 GMT
Distribution: na
Lines: 15

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?