Half-Tone Program for Monochrome Suns Wanted

[John S. Watson]

/*********************************************************************/

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: wat...@ames-titan.arpa
UUCP: ...!nike!watson

[Ponte]

In article <6...@nike.UUCP>, wat...@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).