Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!gatech!prism!vsserv!loligo!pepke
From: pepke@loligo (Eric Pepke)
Newsgroups: comp.graphics
Subject: Re: How to map 24-bit RGB to best EGA/VGA palette?
Keywords: RGB EGA VGA color
Message-ID: <126@vsserv.scri.fsu.edu>
Date: 28 Aug 89 18:36:02 GMT
References: <3129@cbnewsm.ATT.COM> <7743@cbmvax.UUCP> <13319@well.UUCP> <586@celit.com> <4862@eos.UUCP> <13381@well.UUCP>
Sender: news@vsserv.scri.fsu.edu
Reply-To: pepke@loligo.UUCP (Eric Pepke)
Distribution: na
Organization: Supercomputer Computations Research Institute
Lines: 21

In article <13381@well.UUCP> gors@well.UUCP (Michael Sierchio) writes:
>Actually, doing R, G & B separately has a few problems -- that's "taxicab"
>distance, rather than Euclidean distance, for one -- the other is that such
>an error measure relies on a uniform color metric, and the RGB cube is not
>uniform, in that equidistant colors in the color cube are not equidistant
>to the "standard" observer's perceptual apparatus.

One could try other color spaces, such as HSV for example.  I have not done
this.  However, I have done the brighness quantizations in perceptual space,
that is, brightness corrected for logarithmic eyeball response and the gamma
of the tube.  I did not spend a lot of time on this, but the few pictures
that I tried indicated that the difference in quality was not worth writing
home about.

Eric Pepke                                     INTERNET: pepke@gw.scri.fsu.edu
Supercomputer Computations Research Institute  MFENET:   pepke@fsu
Florida State University                       SPAN:     scri::pepke
Tallahassee, FL 32306-4052                     BITNET:   pepke@fsu

Disclaimer: My employers seldom even LISTEN to my opinions.
Meta-disclaimer: Any society that needs disclaimers has too many lawyers.