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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML><HEAD><TITLE>Pnmquantall User Manual</TITLE></HEAD>
<BODY>
<H1>pnmquantall</H1>
Updated: 05 March 2012
<BR>
<A HREF="#index">Table Of Contents</A>

<H2>NAME</H2>

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

<H2 id="synopsis">SYNOPSIS</H2>

<B>pnmquantall</B>

[<B>-ext</B> <I>extension</I>] <I>ncolors</i> <i>netpbm_file</I>...

<p>Note that the usual syntax rules for Netpbm programs <em>don't apply</em>
to this program.  For example, you can't abbreviate -ext and you can't put
it anywhere on the line you want.


<H2 id="description">DESCRIPTION</H2>

<p>This program is part of <a href="index.html">Netpbm</a>.

<p><b>pnmquantall</b> takes a bunch of Netpbm image files as input, chooses
<I>ncolors</I> colors to best represent all of the images, maps the
existing colors to the new ones, and <strong>overwrites the input
files</strong> with the new quantized versions.

<P>If you don't want to overwrite your input files, use the
<B>-ext</B> option.  The output files are then named the same as the
input files, plus a period and the extension text you specify.

<P>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 display 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 <b>pnmquant</b>; <b>pnmquantall</b> solves it for multiple images.

<P>Note that another approach to this problem is to pre-select a set
of colors and then use <b>pnmremap</b> to separately quantize each PPM
to that set.)

<p>This is a rather simple program that runs <b>pnmcolormap</b> and
<b>pnmremap</b>.  If you are considering using it in a program of any
sophistication, you should probably just run those programs directly.
Even if you are typing it, you may want to do the steps manually because
it gives you access to the various options of <b>pnmcolormap</b> and
<b>pnmremap</b> for doing the quantization differently.


<H2 id="seealso">SEE ALSO</H2>

<B><A HREF="pnmquant.html">pnmquant</A></B>,
<B><A HREF="pnmremap.html">pnmremap</A></B>,
<B><A HREF="pnmcolormap.html">pnmcolormap</A></B>,
<B><A HREF="pnm.html">pnm</A></B>

<HR>
<A NAME="index">&nbsp;</A>
<H2>Table Of Contents</H2>
<UL>
<LI><A HREF="#synopsis">SYNOPSIS</A>
<LI><A HREF="#description">DESCRIPTION</A>
<LI><A HREF="#seealso">SEE ALSO</A>
</UL>
</BODY>
</HTML>