ppmquantall
run ppmquant on a bunch of files all at once, so they share a common colormap
see also :
ppmquant
Synopsis
ppmquantall
[-ext extension] ncolors ppmfile
...
add an example, a script, a trick and tips
examples
source
echo Performing quantization to 32
colours
ppmquantall 32 *.ppm
echo Converting to xpm format again
for i in *.ppm
do
echo -n $i
" "
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
specify.
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.)
see also
ppmquant ,
ppm
author
Copyright (C)
1991 by Jef Poskanzer.