ppmquantall(1) - phpMan

ppmquantall(1) General Commands Manual ppmquantall(1)

NAME
ppmquantall - run ppmquant on a bunch of files all at once, so they share a common col-
ormap

SYNOPSIS
ppmquantall [-ext extension] ncolors ppmfile ...

DESCRIPTION
Takes a bunch of portable pixmap as input. Chooses ncolors colors to best represent all
of the images, maps the existing colors to the new ones, and overwrites the input files
with the new quantized versions.

If you don't want to overwrite your input files, use the -ext option. The output files
are then named the same as the input files, plus a period and the extension text you spec-
ify.

Verbose explanation: Let's say you've got a dozen pixmaps that you want to display on the
screen all at the same time. Your screen can only display 256 different colors, but the
pixmaps have a total of a thousand or so different colors. For a single pixmap you solve
this problem with ppmquant; this script solves it for multiple pixmaps. All it does is
concatenate them together into one big pixmap, run ppmquant on that, and then split it up
into little pixmaps again.

(Note that another way to solve this problem is to pre-select a set of colors and then use
ppmquant's -map option to separately quantize each pixmap to that set.)