
Here's source and documentation for a program to convert picture files into
postscript and print black and white halftones on an Apple laser writer.
It sends postscript to the printer using the "lpr" line printer spooler.
The postscript interpreter in the laser writer does the actual halftoning.

The program has options for labeling the picture, displaying the luminance or
just one channel, gamma correction, negation, dithering, and positional control,
as well as transmission to the laser writer at 1, 2, 4, or 8 bit precision.
It's similar to the code recently posted to comp.sources.wanted and
comp.graphics by Mark Majka (majka@ubc-vision.uucp), but with more options.

Enjoy!

Has anyone experimented with sending bitmaps at 300dpi resolution to take
advantage of the halftone bypass feature described in the Postscript book?
Or has anybody written their own postscript code for halftoning in order to
get around the current limit of 32 gray levels?  Please send me mail if you
have.

Paul Heckbert
PIXAR				415-499-3600
P.O. Box 13719			UUCP: {sun,ucbvax}!pixar!ph
San Rafael, CA 94913		ARPA: ph%pixar.uucp@ucbvax.berkeley.edu

