Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!uxc.cso.uiuc.edu!uxc.cso.uiuc.edu!ux1.cso.uiuc.edu!phil
From: phil@ux1.cso.uiuc.edu
Newsgroups: comp.graphics
Subject: Re: GIF viewers are inconsistent
Message-ID: <5300019@ux1.cso.uiuc.edu>
Date: 22 Jun 89 15:55:00 GMT
References: <5300015@ux1.cso.uiuc.edu>
Lines: 16
Nf-ID: #R:ux1.cso.uiuc.edu:5300015:ux1.cso.uiuc.edu:5300019:000:698
Nf-From: ux1.cso.uiuc.edu!phil    Jun 22 10:55:00 1989


> GIF is restricted to 256 unique colors? How is one to convert Amiga HAM
> images (with up to 4096 unique colors) to GIF? Some will work, but others
> won't.

TIFF allows true RGB colors, and that result in 16777216 colors or more.
Conversion to GIF obviously must distort the colors some.  Better programs
will be able to better estimate a good GIF pallette to use from the frequency
of usage of the whole color range.

This is also one of the drawbacks of GIF.  TIFF does not allow pallettes in
the current version I have docs for, but this is less of a drawback since a
GIF file can be converted to a TIFF by just mapping the pallette into each
pixel.

--Phil howard--  <phil@ux1.cso.uiuc.edu>