Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!yale!umich!caen!uakari.primate.wisc.edu!ra!Ra.msstate.edu!ricks From: ricks@EE.MsState.Edu (Rick Schumeyer) Newsgroups: comp.graphics Subject: Re: JPEG (was Re: Next machine as animation platform) Message-ID: Date: 16 Nov 90 04:40:27 GMT References: > <342@van-bc.wimsey.bc.ca> Sender: usenet@ra.MsState.Edu Organization: Mississippi State University Lines: 15 Nntp-Posting-Host: zeus.erc.msstate.edu In-reply-to: jtc@van-bc.wimsey.bc.ca's message of 14 Nov 90 18:59:50 GMT >In short, JPEG is a lossy compression algorithm. That means that some >information is discarded when an image is encoded, and the reconstructed >image is different than the source image. For a lot of images, "close" >is good enough, so lossy compression is a win. I believe there is an extension to the JPEG standard to allow lossless compression. I don't have the details in front of me, but I'm pretty sure that DPCM is used after the DCT if lossless is desired. -- Rick Schumeyer ricks@ee.msstate.edu Drawer EE, Mississippi State, MS, 39762. (601)325-3660