Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!ucbvax!bloom-beacon!eru!kth.se!cyklop.nada.kth.se!news From: d88-jwa@byse.nada.kth.se (Jon W{tte) Newsgroups: comp.compression Subject: Re: JPEG compression errors ?! Message-ID: Date: 5 Jun 91 08:52:51 GMT References: <1991Jun4.223719.2958@qualcomm.com> Sender: news@nada.kth.se (Mr News) Organization: Royal Institute of Technology, Stockholm, Sweden Lines: 26 In-reply-to: rdippold@cancun.qualcomm.com's message of 4 Jun 91 22:37:19 GMT @cancun.qualcomm.com (Ron Dippold) writes: >stupid thing to do. JPEG works better (gives smaller output with >better output) if applied to the original 24bit RGB source than >if applied to the already-quantified 8-bit GIF images. This is Well, get this. GIF to JPEG works great for me on digitized GIF files of resolution 640x400x8 or better (which are the majority). With no visible loss of fidelity it compresses down to 10% to 25% of the original GIF Hmm, well, to each his own. I didn't know GIF supported better than the x8 - it doesn't in the spec sheet _I_ look at. Look at it this way: the GIF you have must come from somewhere. From what I know, there are no GIF-generating scanners, no, they generate 24bit images which have to be quantified and color-index-coded into gif images. Why not go after the sources ? In a few years, of course, this discussion will be academic, but I suggest people really try to get the originals for JPEG encoding, since the gain is so obvious. -- Jon W{tte h+@nada.kth.se - Speed !