# ppmquantall(1) - man - phpMan

[ppmquantall(1)](https://www.chedong.com/phpMan.php/man/ppmquantall/1/markdown)                         General Commands Manual                        [ppmquantall(1)](https://www.chedong.com/phpMan.php/man/ppmquantall/1/markdown)



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


## 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 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 con‐
       catenate 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**(1)](https://www.chedong.com/phpMan.php/man/ppmquant/1/markdown), [**ppm(5)](https://www.chedong.com/phpMan.php/man/ppm/5/markdown)**


## AUTHOR
       Copyright (C) 1991 by Jef Poskanzer.



                                            27 July 1990                              [ppmquantall(1)](https://www.chedong.com/phpMan.php/man/ppmquantall/1/markdown)