wheel@utastro.UUCP (Craig Wheeler) (08/06/86)
I was reading an post on the local bulletin board that rumored Apple had come up with an algorithm for shrinking paint documents in a 31:1 ratio. Imagine a 31K picture saved as 1K on disk. Wow. It said that this would be in great use for the "next mac" (whichever prototype Apple will release) as it would require more memory to store a picture, what with a larger screen and gray scales. Gray scales? Really? I was thinking a while ago that if they didnt come out with a color display, at least they could develop a mac with real grays and shadings. Imagine the quality of digitized images! Any truth to this? If this gets posted twice, I apologize. I was seconds away from saving it when a massive power surge wreaked havoc on my mac (and the modem, and the lights, etc) Lucky I have I surge supressor. Rob Wheeler
chuq@sun.uucp (Chuq Von Rospach; Lord of the OtherRealms) (08/08/86)
> I was reading an post on the local bulletin board that rumored Apple had come > up with an algorithm for shrinking paint documents in a 31:1 ratio. Imagine > a 31K picture saved as 1K on disk. Wow. Wow is right. The rumor is almost definitely wrong. Compression technology of a random bitstream is lucky to get 50% compaction. The compress program used for passing news around averages between 35% and 45%. This may be a "best case" compression, something unrealistic like a Macpaint image of all white or black pixels (neither of them very useful). I doubt seriously they can get even close to that on a normal bitmap. Think about it logically -- a 31:1 ratio implies that each bit in the compressed file needs to hold information to recreate 31 other bits. Not very realistic. > Gray scales? Really? I was thinking a while ago that if they didnt come out > with a color display, at least they could develop a mac with real grays and > shadings. Imagine the quality of digitized images! Any truth to this? The Dvorak rumor mill has come up with this one. Lots of people who have signed non-disclosures giggle at Dvorak, but can't say anything more. The rumor was NOT for a Mac, but for the first in a new family of computers that would not neccesarily be Mac compatible, but would be the first Unix based machine. I wouldn't hold my breath for it. chuq -- Chuq Von Rospach chuq%plaid@sun.COM CompuServe: 73317,635 {decwrl,hplabs,ihnp4,seismo}!sun!plaid!chuq O how they cling and wrangle, some who claim Of Brahamana and recluse the honoured name! For, quarrelling, each to his view they claim, Such folk see only one side of a thing. -- Buddha -- The Elephant and the Blind Men
whp@cbnap.UUCP (W. H. Pollock x4575 3S235) (08/13/86)
In article <5963@sun.uucp> chuq@sun.uucp (Chuq Von Rospach; Lord of the OtherRealms) writes: >> I was reading an post on the local bulletin board that rumored Apple had come >> up with an algorithm for shrinking paint documents in a 31:1 ratio. Imagine >> a 31K picture saved as 1K on disk. Wow. > >Wow is right. The rumor is almost definitely wrong. Compression technology >of a random bitstream is lucky to get 50% compaction. The compress program >used for passing news around averages between 35% and 45%. Ahh, but bitmaps are not "random bitstreams"! I read an article in Abacus last month which describes a method to compress bitmaps to 0.18 bits/pixels, which is an 82% gain. (The authors also claimed 2.2 bits/character for text). The method involves adoptive modeling and dynamic Markov models. Wayne H. Pollock, UUCP: ...{ihnp4,cbatt}!cbnap!whp DELPHI: WHP GEnie: W.POLLOCK "The opinions expressed above are ficticious. Any resemblance to the opinions of persons living or dead is purely coincidental."