From albanycs!leah:rsb584 Mon Nov 30 11:55:43 1987 Received: by albanycs.albany.edu (5.54/4.8) id AA04434; Mon, 30 Nov 87 11:06:43 EST Date: Mon, 30 Nov 87 11:06:39 EST From: albanycs!leah:rsb584 (Raymons Brand) Received: by leah.Albany.EDU (5.58/1.1) id AA03973; Mon, 30 Nov 87 11:06:39 EST Message-Id: <8711301606.AA03973@leah.Albany.EDU> To: albanycs:beowulf!rsbx >From cyrus@hi.UUCP Sun Nov 29 12:39:53 1987 Path: leah!uwmcsd1!ig!jade!ucbcad!ames!hc!hi!cyrus From: cyrus@hi.UUCP (Tait Cyrus) Newsgroups: comp.graphics Subject: dithers Keywords: dithers Message-ID: <20906@hi.UUCP> Date: 29 Nov 87 17:39:53 GMT Organization: U. of New Mexico, Albuquerque Lines: 59 Currently I have at my disposal the following 8 bit deep b/w dither routines: 1) Perform dithering using ordered (matrix) technique, optimized for 45 degree main axis. Output is an X bitmap. The matrix used is: unsigned char t[8][8] = { 52, 44, 36, 124, 132, 140, 148, 156, 60, 4, 28, 116, 220, 228, 236, 164, 68, 12, 20, 108, 212, 252, 244, 172, 76, 84, 92, 100, 204, 196, 188, 180, 132, 140, 148, 156, 52, 44, 36, 124, 200, 228, 236, 164, 60, 4, 28, 116, 212, 252, 244, 172, 68, 12, 20, 108, 204, 196, 188, 180, 76, 84, 92, 100 }; 2) Perform dithering using ordered (matrix) technique. Ref. Bayer. Output is in the form of an X bitmap. The matrix used is: /* Dither matrix, four-point star type */ unsigned char t1[5][5] = { 40, 80, 140, 120, 20, 60, 170, 210, 190, 100, 150, 240, 250, 230, 160, 90, 200, 220, 180, 50, 10, 110, 130, 70, 30 }; /* Dither matrix, box type */ unsigned char t2[5][5] = { 138, 230, 5, 219, 107, 87, 46, 179, 67, 148, 189, 26, 250, 15, 199, 158, 77, 168, 56, 97, 128, 209, 36, 240, 117 }; 3) Dithering by error diffusion. Error is diffused modulo 256 to the pixel to the right and to the three pixels below. My question is: "Does anyone have anyother dithering algorithims, other than the ones mentioned above, that they use and are in the public domain?" I have seen some SUN background that use some 'rather interesting' dithers. For example "yosemite", "shakespeare", "porsche" plus man others. I would very much like to get ahold of some dithers. Thanks in advance -- @__________@ W. Tait Cyrus (505) 277-0806 /| /| University of New Mexico / | / | Dept of EECE - Hypercube Project @__|_______@ | Albuquerque, New Mexico 87131 | | | | | | hc | | e-mail: | @.......|..@ cyrus@hc.dspo.gov or | / | / seismo!unmvax!hi!cyrus @/_________@/