ppmrainbow - Generate a rainbow
ppmrainbow
[
-width=number] [
-height=number] [
-tmpdir=directory] [
-norepeat] [
-verbose]
color ...
This program is part of
Netpbm(1).
ppmrainbow generates a PPM image that fades from one color to another to
another from left to right, like a rainbow.
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 a
transparency 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.
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.
color ... is the list of colors, in order from left to right, to go into
the rainbow.
The first color is added again on the right end of the image unless you specify
the
-norepeat option. This means you can concatenate multiple copies
(tile, as with
pnmtile) to make a continuous larger image.
color is as described for the
argument of the
pnm_parsecolor() library routine .
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.
-
-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.
- -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.
ppmrainbow always creates a directory within this directory and
creates all its files within that directory.
- -verbose
- Print the "commands" (invocations of other Netpbm
programs) that ppmrainbow uses to create the image.
pgmramp(1),
pamseq(1),
pamgradient(1),
ppmmake(1),
ppmfade(1),
ppm(1).
Arjen Bax wrote
ppmrainbow in June 2001 and contributed it to the Netpbm
package. Bryan Henderson wrote this manual in July 2001.
This manual page was generated by the Netpbm tool 'makeman' from HTML source.
The master documentation is at
- http://netpbm.sourceforge.net/doc/ppmrainbow.html