Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!magnus.acs.ohio-state.edu!tut.cis.ohio-state.edu!sei.cmu.edu!fs7.ece.cmu.edu!o.gp.cs.cmu.edu!spot From: spot@CS.CMU.EDU (Scott Draves) Newsgroups: comp.compression Subject: Re: looking for info on image compression Message-ID: Date: 25 Mar 91 14:59:40 GMT References: <1991Mar25.051453.23477@borland.com> Sender: netnews@cs.cmu.edu (USENET News Group Software) Organization: School of Computer Science, Carnegie Mellon University Lines: 34 In-Reply-To: sidney@borland.com's message of 25 Mar 91 05:14:53 GMT In article <1991Mar25.051453.23477@borland.com> sidney@borland.com (Sidney Markowitz) writes: I'm interested on information on compression techniques that are suitable for images, where exact reproduction of the data is not necessary after decompression, as long as the result looks ok as an image. this is usu called "lossey" compression. There are two of current interest, JPEG and HDTV Digicipher. Here are some references (provided to me by hewlett@media-lab, thank you!) G.K Wallace, "Overview of the JPEG (ISO/CCITT) Still Image Compression System, "Visual Communications and Image Processing '89, SPIE, Philadelphia, November 1989 A. Fernandez, R. Ansari, D.J. Gall and C.T. Chen, "HDTV Subband/DCT Coding: Analysis of System Complexity," IEEE Globecom Proceedings, 343.1.1 - 343.1.4, 1990 I've heard that there are, for example, fractal techniques that achieve much better compression on images than The fractal compression is done by Barnesly (sp?) from Georgia Tech, I think. As far as I can tell, it is a money-making hoax. He won't disclose his algorithms unless you pay him lots of money, and I have yet to see an example of an actual compressed image (He has a few images he likes to show, and they *are* generated by ridiculously small quantities of data. But he doesn't show the original.... i wonder why...) -- christianity is stupid Scott Draves communism is good spot@cs.cmu.edu give up