Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!olivea!apple!agate!ucbvax!gnh-starport.cts.com!scottg From: scottg@gnh-starport.cts.com (Scott Gentry) Newsgroups: comp.sys.apple2 Subject: Re: 3200 Gif converters Message-ID: Date: 1 Dec 90 10:36:40 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 30 X-Unparsable-Date: Fri Nov 30 90 at 11:24:10 (EST) In a previous message, Scott Alfter said something like ... "Better yet, write a C program that takes a GIF file and turns it into raw picture data--two 16-bit words for picture size, followed by a stream of 24-bit pixel data. Yes, this would create huge files on your UNIX box, but you then write a separate program to take the 24-bit color data and munge it for whatever graphic mode you want--Hi-Res, double Hi-Res, 320-mode super Hi-Res, 3200-color, or you could even use the 24-bit decoder in conjunction with a converter for almost any graphic mode on any computer. (You won't see it, but damn this line noise I'm getting! :-( ) " Welp, you should really try what you're suggesting sometime. At 24 bits per pixel (8 bits per component), a 320x200 file takes 192,000 bytes. Turns out you don't gain much in terms of quality when you _try_ to expand an image whose components are 4 bit, because the image has already had it's color map reduced. There is virtually no way to synthesize more color in an image than is already present, except in the case of contrast/brightness enhancement. With that in mind, here's how you turn a 4 bit image into a "24 bit raw" as you put it image... multiply each component by 17. Keep in mind, though, unless you've got raw data to start with, you'll never get more than 16 colors from a colormap of a GIF image that originated on the GS. _______________________________________________________________________________ | Scott Gentry * ALPE AFL Scott * I never said that!| | 2051 Mercator Drive * GEnie W.GENTRY * But you never | | Reston, VA 22091 * UUCP: uunet!ingr!ne1300! * know! | | (703) 264-5652 * brnded!scott * Do You? | |_____________________________________________________________________________|