Ppmquantall User Manual(0)			    Ppmquantall User Manual(0)



NAME
       ppmquantall  -  run  Pnmquant  on a bunch of files all at once, so they
       share a common colormap


SYNOPSIS
       ppmquantall

       [-ext extension] ncolors ppmfile...


DESCRIPTION
       This program is part of Netpbm(1).

       ppmquantall takes a bunch of PPM images as input, chooses ncolors  col-
       ors  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 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 PPM  you  solve  this	 problem  with
       pnmquant; ppmquantall solves it for multiple PPMs.  All it does is con-
       catenate them together into one big PPM, run pnmquant on that, and then
       split it up into little PPMs again.

       (Note  that another way to solve this problem is to pre-select a set of
       colors and then use pnmremap to separately quantize each	 PPM  to  that
       set.)


SEE ALSO
       pnmquant(1), pnmremap(1), pnmcolormap(1), ppm(1)


AUTHOR
       Copyright (C) 1991 by Jef Poskanzer.



netpbm documentation		 27 July 1990	    Ppmquantall User Manual(0)