jmarvin@oracle.com (12/05/90)
In article <1990Nov28.192940.30995@uokmax.ecn.uoknor.edu> drtiller@uokmax.ecn.uoknor.edu (Donald Richard Tillery Jr) writes: >The 24 bit boards are coming...the 24 bit boards are coming! > >Now for the catch (ain't there always one?)....those 24 bit RGB IFF >files are HUGE! I have 11 of them right now and they range from >300K to almost 850K! > >I have heard of some such algorithms and one type in particular where >the resulting image IS NOT an exact duplicate of that which started >out. But the resulting reduction is up to 90% ! Now if only a .1% >or less distortion is introduced, I think we can live with that (it >amounts to about 1 radical pixel every other line) but I don't know >any specifics about it. Rumour has it that it is the technique used >for telephone face-to-face transmissions. Anyone have any info on >this? > >Barring that, does anyone have any info on some effective image >compression techniques that might make use of the 2 dimensional >quality of images versus the 1 dimentional nature of programs? > What you want is the JPEG compression. It's only a draft proposal, but it's close enough to use. To get the spec: Dr. W. B. Pennebaker IBM Coproration Hawthorne Resarch Laboratory P. O. Box 704 Yorktown Heights, NY 10598 914/784-6566 914/784-6288 (FAX) Ask for the latest spec (rev 8) This technique uses Discrete Cosine Transforms and Quantization, and a good reference on that is: Discrete Cosine Transform -- Algorithms, Advantages, Applications K. R. Rao & P Yip Academic Press ISBN 0-12-580203-X And, sorry, I don't have time to whip off a public domain version for Ami. But I wanted to seed others who might! > >Rick Tillery >(drtiller@uokmax.ecn.uoknor.edu) > ******************************************************************* * John W. S. Marvin * There are times when the wolves * * Oracle Multimedia Development * are silent, and the moon is * * jmarvin@oracle.com * howling... * *******************************************************************
dtiberio@csserv2.ic.sunysb.edu (David Tiberio) (12/06/90)
A friend of mine has writtend a program that compresses 3d renderings.
I have the details, but it would be better for you to ask him via PLINK.
He has compacted an 800 polygon file to 300 polygons, which is pretty good.
This is a must for all 3d users. He can also transfer between Amiga and
Atari ST (he did this because one of his friends just so happens to be an
ST owner, and they wanted to trade pictures). Both programs were written
on the IBM Bridgeboard and were ported to Amiga C. I do not know how the
Bridgeboard multitasks, but if it does without slowing the Amiga, then
the IBM version will keep you multitasking more efficiently.
Contact him at PLINK:DDD MEN
in case the D's like like O's, that's "3d MEN"
David Tiberio SUNY Stony Brook 2-3605 AMIGA Toto Productions DDD MEN