watson@nike.UUCP (John S. Watson) (10/16/86)
/*********************************************************************/ Does anybody have a public domain half-tone program that will take 3 image files (Red Green and Blue), and produce a half-tone image/file, suitible for displaying in monochrome screen? Currently we have many monochrome Sun workstations, but only a couple of color Suns. It would be nice to preview an image on the monochrome Sun a few times before fighting to get on the color Sun. I have the color-dither program that recently came accross the net, which takes 3 images files (RGB) and makes a color image for the color Sun, so what I need is a program that does the same thing, only produces a monochrome image. Thanx in Advance, John S. Watson NASA Ames Research Center ARPA: watson@ames-titan.arpa UUCP: ...!nike!watson
ponte@ge-dab.UUCP (Ponte) (10/21/86)
In article <667@nike.UUCP>, watson@nike.UUCP (John S. Watson) writes: > /*********************************************************************/ > > Does anybody have a public domain half-tone program that will take > 3 image files (Red Green and Blue), and produce a half-tone image/file, > suitible for displaying in monochrome screen? > There is a simple formula to convert a color value (RGB) to a monochrome value (Intensity). It is the same way a color picture is shown on a black and white TV. The equation is: I = RED * 0.30 + GREEN * 0.59 + BLUE * 0.11 The percentage values used for multiplying all add up to 1. (.3+.59+.11). If this information does indeed answer your question, it wouldn't be hard for you to write your own program to read in a color value (RGB) and spit out an intensity value (I). My source of information is "Introduction to Computer Graphics" by Foley and VanDam. If you have access to a copy of this book you may want to look at pg. 613, (Chapter 17.15).