Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uunet!convex!rosenkra From: rosenkra@convex.com (William Rosencranz) Newsgroups: comp.sys.atari.st Subject: Re: Demo of 15 gray levels on ST. Message-ID: <1991Jun17.231200.1623@convex.com> Date: 17 Jun 91 23:12:00 GMT References: <1991Jun15.000225.13409@ns.network.com> Sender: usenet@convex.com (news access account) Organization: CONVEX Computer Corporation, Richardson, Tx., USA Lines: 37 Nntp-Posting-Host: convex1.convex.com In article <1991Jun15.000225.13409@ns.network.com> logajan@ns.network.com (John Logajan) writes: >This is a self contained demo of using "flicker" techniques to produce >15 gray scale levels on a regular ST (normally only 8 levels are possible.) interesting... i posted to c.{s,b}.a.st about 2+ weeks ago a new version of mgif which now does flicker, too. only now mgif does more than just display. you can do histo equalization, contrast stretching, inversion, thresholding, convolutions of all sorts, median filtering, blurring, and a raft of other image processing. i have a new version ready to go (posted 3.2, current is 3.5) which also saves the flicker screens (i use 3) to a file which is smaller than gif and can be viewed by mgif, too. new version also reads PI2 and PI1 files. maybe i should upload to a.a instead of the "normal" channels of the binaries/source groups? incidently, as always, i post complete source. mgif works with all GIF files (GIF87a, that is). it is still slow, but can be made to go faster. i opted for modularity over speed. mgif only runs on mono systems. the binary posted needs 1.5MB memory or so. there are easy hooks to support spectrum and other formats. just read the file into a raster and colormap (RGB). flicker is tons better than just dithering. you'd be suprised just how good an image can look. the flicker is virtually unnoticable, too. no more standing 10 feet away or squinting! john, i'd be interested in your technique. mgif does flicker by passing a ptr to a grayscale image to the screen drawing routine which then returns a ptr to the (sequential) flicker screens. it is very modular. i am going to have a look at yours. i assume it works on mono... -bill rosenkra@convex.com (it really only works on gifs up to 400,000 pixels without a recompile. that is 640x600+, however) -- Bill Rosenkranz |UUCP: {uunet,texsun}!convex!c1yankee!rosenkra Convex Computer Corp. |ARPA: rosenkra%c1yankee@convex.com