ppmrainbow
Updated: 1 July 2001
Table Of Contents
NAME
ppmrainbow - Generate a rainbow
SYNOPSIS
ppmrainbow
[-width=number]
[-height=number]
[-tmpdir=directory]
[-norepeat]
[-verbose]
color ...
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 value.
DESCRIPTION
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
-norepeat option.
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 ppmrainbow.
OPTIONS
- -width number
-
The width in pixels of the output image.
Default is 600.
- -height number
-
The height in pixels of the output image.
Default is 8.
- -norepeat
- This option makes ppmrainbow end the rainbow with the last
color you specify. Without this option, ppmrainbow adds the
first color you specify to the right end of the rainbow as if you had
repeated it. (I don't understand the point of this default behavior;
it exists today just for backward compatibility).
- -tmpdir
- The directory specification of the directory ppmrainbow is
to use for temporary files.
Default is the value of the TMPDIR environment variable, or
/tmp if TMPDIR is not set.
- -verbose
- Print the "commands" (invocations of other Netpbm
programs) that ppmrainbow uses to create the image.
SEE ALSO
ppmmake,
pamcomp,
pbmtext,
ppmfade,
pnmrotate,
pamflip,
ppm.
AUTHOR
Arjen Bax wrote ppmrainbow in June 2001 and contributed it
to the Netpbm package. Bryan Henderson wrote this manual in July
2001.
Table Of Contents