[comp.graphics] LZW data compression.

gray@toffee.it.udel.edu (Scott Gray) (03/06/90)

I realize that I am posting this at the _great_ risk of being flamed, and
yes I have read the weekly posting, but I have been wracking my brains
for too long and need some help.

Ok, for some odd reason I have never been able to find a sun rasterfile
to GIF converter, I have looked everywhere.  So I have taken it upon myself
to write one. Well, everything works fine up until I get to the actual data
compression.

Could someone PLEASE give me some insight on how to implement the code for LZW
compression, or better yet, give me some sample code.  I have read the gif.doc
that almost every anon ftp site has, but it really does not give a thorough
explanation of it, and I have also looked for the suggested readings that
are in the document, but I can't find them in our library, so any info would
be greatly appreciated.

A second question, related to the last one is: does anyone know the format of
a Sun rasterfile as it occures on the DISK(raw),because I think that it would be
a bit faster go direct rather than going through pixrect.  I understand
the header, but the colormap seems to be in an odd order; not RED[0],GREEN[0],
BLUE[0],RED[1],GREEN[1],BLUE[1],...etc. as expected.

Thanks,
Scott Gray

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+ SCOTT - gray@freezer.it.udel.edu  |  "I'm, BORED BORED BORED BORED!"        +
+      or  god@vax1.acs.udel.edu    |                 - Vivian                +
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