Path: utzoo!attcan!uunet!mcvax!hp4nl!uva!borton
From: borton@uva.UUCP (Chris Borton)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: Greyscale Compression Algorithms
Keywords: Compression Greyscale
Message-ID: <524@uva.UUCP>
Date: 22 Aug 88 15:02:30 GMT
References: <1241@micomvax.UUCP>
Reply-To: borton@uva.UUCP (Chris Borton)
Organization: Faculteit Wiskunde & Informatica, Universiteit van Amsterdam
Lines: 17

In article <1241@micomvax.UUCP> bhickey@micomvax.UUCP (Bruce Hickey) writes:
>The emphhasis should be on speed more than on size reduction. I've heard that
>hypercard performs some type of compression of the images that it uses. Is this
>so? How is it done? 
My understanding is that HyperCard's compression of bitmaps in the files it
saves is thanks to a nifty-wifty super-duper-secret algorithm developed by
Bill Atkinson, and Apple has done everything possible to keep it under wraps.
See the interview with Bill in the front of Danny Goodman's book.

Minor point: HyperCard compresses *bitmaps*, not grey scales.  i.e. 1 bit
 per pixel.  HC doesn't deal with more than that much yet...

-cbb
-- 
Chris Borton	borton%uva@mcvax.{nl,bitnet,uucp} 
(oops, that's rather flakey right now: use borton%uva@hasara5.bitnet)
Rotary Scholar, University of Amsterdam CS