Pnmquantall User Manual(0) Pnmquantall User Manual(0)NAMEpnmquantall - run Pnmquant on a bunch of files all at once, so they
share a common colormap
SYNOPSISpnmquantall
[-ext extension] ncolors netpbm_file...
Note that the usual syntax rules for Netpbm programs don't apply to
this program. For example, you can't abbreviation -ext and you can't
put it anywhere on the line you want.
DESCRIPTION
This program is part of Netpbm(1)pnmquantall takes a bunch of Netpbm image files as input, chooses ncol‐
ors colors to best represent all of the images, maps the existing col‐
ors to the new ones, and overwrites the input files with the new quan‐
tized 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.
The purpose is this: Let's say you've got a dozen PPMs that you want to
display on the screen all at the same time. Your screen can only dis‐
play 256 different colors, but the PPMs have a total of a thousand or
so different colors. For a single image you solve this problem with
pnmquant; pnmquantall solves it for multiple images.
Note that another approach to this problem is to pre-select a set of
colors and then use pnmremap to separately quantize each PPM to that
set.)
This is a rather simple program that runs pnmcolormap and pnmremap. If
you are considering using it in a program of any sophistication, you
should probably just run those programs directly. Even if you are typ‐
ing it, you may want to do the steps manually because it gives you
access to the various options of pnmcolormap and pnmremap for doing the
quantization differently.
SEE ALSOpnmquant(1) , pnmremap(1) , pnmcolormap(1) , pnm(1)netpbm documentation 05 March 2012 Pnmquantall User Manual(0)
