Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!decwrl!apple!vsi1!zorch!xanthian From: xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) Newsgroups: alt.sources.d Subject: Re: Compressing alt.sex.pictures files Message-ID: <1990Aug29.154719.17301@zorch.SF-Bay.ORG> Date: 29 Aug 90 15:47:19 GMT References: <1990Aug27.154419.25882@mcs.anl.gov> <1990Aug28.192024.22435@zorch.SF-Bay.ORG> <1990Aug29.000054.28444@murdoch.acc.Virginia.EDU> Organization: SF Bay Public-Access Unix Lines: 29 In article <1990Aug29.000054.28444@murdoch.acc.Virginia.EDU> dmm0t@hudson.acc.Virginia.EDU (David M. Meyer) writes: >Compressing a.s.p would be a wonderful idea, except that almost all >of the traffic is in .GIF pictures, which are already compressed >pretty thoroughly. I'm not sure exactly what the methods used >are, but neither PKZIP nor compress actually shrinks .GIF files. Right. The idea is to come up with a much better way of compressing the raw pixel data, and then incorporate that new compression scheme in "all" the picture handling software. This means the compression scheme must be 1) public domain, 2) reasonably, but not necessarily blindingly fast (it is worth spending _hours_ to compress a file if you can make it 20% the size any other compression scheme can make it, and then save that space on every USENet site and every home computer's storage!), 3) able to decompress very fast (paying a high decompression cost at every site doesn't have the same economic balance that a high compression cost at the site of origin has), 4) available in source code; and 5) widely ported. This is not a short term "fix" that we can band-aid into a.s.p next week; but if a highly effective scheme is found, it will spread itself fast enough; the economic motivation to save disk space is everywhere. Note that it is sufficient that the scheme found compress _realistic_image_ data well; it doesn't have to compress random input at all well, nor does it need to do well on text; image data is a worthwhile target for compression in its own right, and at its present rate of dissemination, will probably rapidly overwhelm in size the sum of all other stored machine readable data. Kent, the man from xanth.