Re: JPEG Compression

[P3D Larry Berlin <lberlin@xxxxxxxxx>]

>Date: Wed, 23 Apr 1997 
>From: P3D Greg Marshall  comments:
>.....................
>I agree that JPEG is always preferable to (256 color or less) GIF 
>for "real world" images.  But hasn't GIF been extended to sup-
>port 24-bit images?  Where can I find out more about PNG?
>JPEG really is limited to 8 bits per channel because the output
>of the DCT is truncated to 11 bits, which isn't really quite enough
>to handle 8-bit input without error.

GIF is limited to palettized colors. I've heard that it can support much
higher color counts, but computers don't generally use palettes for anything
over 256 colors. That's what forms the limit of usefulness for GIF, (in
addition to the painful *GIF tax*).

Here's a link relating to PNG. I think it has info on the complete format or
a link to more. The full specs are on the web so a search will provide a lot
more references.

http://codelab.siegelgale.com/solutions/pnglive2.html

Larry Berlin

Email: lberlin@xxxxxxxxx
http://www.sonic.net/~lberlin/
http://3dzine.simplenet.com/


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