[-width=number] [-height=number] [-tmpdir=directory] [-norepeat]
[-verbose] color ...
This program is part of Netpbm.
ppmrainbow generates a PPM image that fades from one color to another
to another from left to right, like a rainbow. The colors are those
you specify on the command line, in that order. The first color is
added again on the right end of the image unless you specify the
If you want a vertical or other non-horizontal rainbow, run the output
through pnmrotate or pamflip.
One use for such a rainbow is to compose it with another image under
an alpha mask in order to add a rainbow area to another image. In
fact, you can make rainbow-colored text by using pbmtext, pamcomp, and
pgmramp does a similar thing for grayscale images.
If you just want an image containing all the possible colors (for some
kind of processing; not to look at), see pamseq.
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 equals signs between an option name and its
pgmramp, pamseq, pamgradient, ppmmake, ppmfade, ppm.
Arjen Bax wrote ppmrainbow in June 2001 and contributed it to the
Netpbm package. Bryan Henderson wrote this manual in July 2001.
netpbm documentation 14 October 2005 Ppmrainbow User Manual(0)