Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!uwm.edu!wuarchive!zaphod.mps.ohio-state.edu!lavaca.uh.edu!uhnix1!sugar!peter From: peter@sugar.hackercorp.com (Peter da Silva) Newsgroups: alt.sources.d Subject: Re: Compressing alt.sex.pictures files Message-ID: <6467@sugar.hackercorp.com> Date: 29 Aug 90 13:00:55 GMT References: <1990Aug27.154419.25882@mcs.anl.gov> <1990Aug28.192024.22435@zorch.SF-Bay.ORG> Reply-To: peter@sugar.hackercorp.com (Peter da Silva) Organization: Sugar Land Unix - Houston Lines: 13 In article <1990Aug28.192024.22435@zorch.SF-Bay.ORG> xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) writes: > Hmmm. Good idea. Here's one suggestion for an experiment. Somewhere on > the net, a month or two back, there was a suggestion that a good way to > compress realistic images was to XOR scan lines after the first with their > predecessor line, then LZW compress the output. I believe that XORing alternate scan-lines and run-length-encoding the result would do a better job. I've heard of this algorithm being pretty effective in past discussions. Should one do this with the image bitplane-mapped or pixel-mapped? -- Peter da Silva. `-_-' .