Xref: utzoo comp.compression:747 alt.sex.pictures.d:4400 Path: utzoo!utgpu!cs.utexas.edu!wuarchive!uunet!snorkelwacker.mit.edu!bloom-beacon!eru!kth.se!cyklop.nada.kth.se!news From: d88-jwa@byse.nada.kth.se (Jon W{tte) Newsgroups: comp.compression,alt.sex.pictures.d Subject: Re: JPEG compression errors ?! Message-ID: Date: 13 Jun 91 10:43:18 GMT References: <13405@pt.cs.cmu.edu> <1991Jun12.084749.329@nntp-server.caltech.edu> <1991Jun12.215238.18301@nntp-server.caltech.edu> Sender: news@nada.kth.se (Mr News) Organization: Royal Institute of Technology, Stockholm, Sweden Lines: 17 In-reply-to: madler@nntp-server.caltech.edu's message of 12 Jun 91 21:52:38 GMT > madler@nntp-server.caltech.edu (Mark Adler) writes: comparison. I guess my point was that 2:1 sounds low to me for lossless natural image compression. So what's a "decent" compression ratio ? Remember, GIF suffers from a nasty loss in the 24-bit-to-8-bit transition (which also is a 3:1 compression - at great cost) I guess crawling along some space-filling curve and encode the deltas for each color component using arithmetic coding could do better sometimes, but that algo's "close" to the JPEG lossless. -- Jon W{tte h+@nada.kth.se - Speed !