Path: utzoo!attcan!uunet!munnari.oz.au!cluster!metro!ipso!fawlty!johnmac
From: johnmac@fawlty.towers.oz (John MacLean)
Newsgroups: comp.sys.apple
Subject: Re: HR|DHR -> GIF Revisited
Message-ID: <178@fawlty.towers.oz>
Date: 20 Feb 90 22:21:11 GMT
Organization: Tower Technology, Lane Cove, NSW, Australia
Lines: 23

>> Is there a program for the // (not gs) that'll convert hires and double-
>> hires pictures into .gif format?  I know we got one that'll read them,
>> but the only program I've seen that'll change into .gif is for the gs
>> (written by the guy that did the reader for the //+ec).

Reading GIF files is a simple process.
Writing GIF files is more complex: To do things fast and effeciently,
requires a table of 2^20 = 1 Meg of 12 bit values (make this 16 bit values
so things are word aligned).
I have 2 versions of my GIF writer in 65816:
One uses this full table and is *very fast*;
the other uses complex hashing scheme and uses < 64K of buffers.
I also have one or two 'C' versions of GIF writers (not written by me) that
I have collected.
There are 6502/65C02 compilers around, so this sort of thing could be done,
but I for one would not like to code a GIF writer in 6502/65C02 directly.

Regards, John MacLean.
-- 
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