pgmramp -lr|-tb|-rectangle|-ellipse -maxval=maxval width height
All options can be abbreviated to their shortest unique prefix. You
may use two hyphens instead of one to designate an option. You may
use either white space or an equals sign between an option name and
This program is part of Netpbm.
Generates a graymap of the specified size containing a black-to-white
ramp. These ramps are useful for multiplying with other images, using
The ramp is linear in brightness, not intensity. I.e. the gamma-cor-
rected sample values in the PGM rise linearly with distance from the
corner of the image. If you want a ramp that is linear in light
intensity, use pnmgamma with pgmramp.
To generate a simple ramp of all the values from 0 to maxval, and not
necessarily a graphic image, use pamseq.
ppmrainbow does something similar to what pgmramp does, but for color.
The image fades between two colors of your choice.
You must specify exactly one of the ramp type options.
-lr A left to right ramp.
-tb A top to bottom ramp.
pamarith, pnmgamma, pamseq, ppmrainbow, pamgradient,
Copyright (C) 1989 by Jef Poskanzer.
netpbm documentation 04 June 2002 Pgmramp User Manual(0)