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From: paulf@shasta.Stanford.EDU (paulf)
Newsgroups: alt.graphics.pixutils,comp.graphics
Subject: Re: Gif picture re-ordering
Message-ID: <163@shasta.Stanford.EDU>
Date: 19 Apr 91 18:29:05 GMT
References: <cs442a07.672031798@zaphod>
Organization: The Three Packeteers
Lines: 15

In article <cs442a07.672031798@zaphod> cs442a07@zippy.cs.iastate.edu writes:
>The color numbers are re-ordered so that near-to-each-other pixels are 
>near to each other in color number; 

We considered doing such a thing a while back.  The scheme I proposed was
to take the color map, convert to YIQ, sort the colors according to I,
greycode the list (so colors close in intensity are close bitwise), and 
convert the image.

While this would do wonders for true Lempel - Ziv, it won't do anything
for Lempel - Ziv - Welch, which is a BYTE oriented compression scheme.
So, as my Math Phil prof once put it, "the ship sinks".

-=Paul Flaherty, N9FZX      | "Think of it as evolution in action."
->paulf@shasta.Stanford.EDU |       -- Larry Niven and Jerry Pournelle