Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!apple!ames!hc!lanl!beta!pt
From: pt@beta.lanl.gov (Paul A. Thiessen)
Newsgroups: comp.graphics
Subject: Re: GIF viewers are inconsistent
Message-ID: <26680@beta.lanl.gov>
Date: 20 Jun 89 16:15:06 GMT
References: <5300015@ux1.cso.uiuc.edu> <1305@cbnewsc.ATT.COM>
Reply-To: pt@beta.UUCP (Paul A. Thiessen)
Organization: Los Alamos Natl. Labs, Los Alamos, NM
Lines: 25

In article <1305@cbnewsc.ATT.COM> vgopal@cbnewsc.ATT.COM (venu.p.gopal) writes:
>disappear.  The differences mainly exist because the GIF colors
>specifications have to be approximated by what the display card can
>show and different programs have different methods.
>
>Venu P. Gopal
>UUCP:	att!ihuxy!vgopal
>Internet: vgopal@ihuxy.att.com
>BITNET: com%"vgopal@ihuxy.att.com"   or   com%"vgopal%ihuxy@research.att.com"
>Silence those silent letters and save the world 500 million keystrokes a day.

More specifially, GIF can handle 8 bits of color resolution, meaning
every color can have red, green, and blue values from 0 to 255. But VGA
is only 6 bits, meaning RGB values from 0..63. So to display on VGA,
the GIF program has to scale the 8 bits down to 6 bits which can cause
color distortion and differences in colors depending on exactly how the
program "crunches" 256 values into 64.

           - Paul

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PAUL THIESSEN                     (Summer only: pt@lanl.gov)
pthiessen@hmcvax.bitnet            ...uunet!jarthur!pthiesse
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