Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!rutgers!att!cbnewsc!vgopal
From: vgopal@cbnewsc.ATT.COM (venu.p.gopal)
Newsgroups: comp.graphics
Subject: Re: GIF viewers are inconsistent
Message-ID: <1362@cbnewsc.ATT.COM>
Date: 22 Jun 89 17:44:03 GMT
References: <5300015@ux1.cso.uiuc.edu> <1305@cbnewsc.ATT.COM> <4623@ficc.uu.net>
Reply-To: vgopal@cbnewsc.ATT.COM (venu.p.gopal)
Organization: AT&T Bell Laboratories
Lines: 22

In article <4623@ficc.uu.net> peter@ficc.uu.net (Peter da Silva) writes:
>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.

Yes, the current GIF standard is restricted to 256 colors only;  however,
each of the 256 colors can be one of 16.7 million colors.  If you are
converting from a 4096 color image, obviously you will lose something.
The 4096 colors, depending on their red, blue and green content, will have
to be mapped to 256 colors that should be selected from the 16.7 million.
There was some discussion on color mapping algorithms in this newsgroup
sometime earlier.

The 256 color restriction is obviously based on the 8-bit byte so that a
color can be represented by a byte.  You can actually do a lot with
256 colors, I have seen a lot of very impressive images.

Venu P. Gopal
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