NAME
ppmcolors - generate a color map of all colors of a certain maxval
SYNOPSIS
ppmcolors
[-maxval=maxval]
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 its
value.
DESCRIPTION
ppmcolors
generates a PPM color map containing all the colors representable with
a certain maxval.
A PPM color map is a regular PPM image that is used by some programs to
define a set of colors.
ppmcolors
generates a one row PPM image that contains one pixel of each color
representable by the maxval you choose. The maxval of the PPM image is
that maxval. Note that you can change the maxval of the color map by
running the output of
ppmcolors
through
R pnmdepth .
As long as the new maxval is a multiple of the original, the resulting
set of colors will be identical. If the new maxval is not a multiple,
the resulting set of colors will be slightly different.
When you select a maxval of 5 (which is the default), you get a color
map of the set of "web safe" colors as defined by Netscape. Most web
browsers guarantee that they can produce at least these 216 colors
(215 plus black).
pnmcolormap
is another program to generate a color map. It chooses a set of colors
designed to represent the colors in a specified image (or simply the set
of all the colors in that image, if you choose).
pgmramp
performs a similar function for PGM images.
OPTIONS
-maxval=maxval
This is the maxval of the generated color map. Default is 5.
SEE ALSO
AUTHOR
By Bryan Henderson, December 2001.
\"Contributed to the public domain.