File: //usr/share/doc/netpbm-10.35.58/userguide/pnm.html
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<H1>pnm</H1>
Updated: 03 October 2003
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<A HREF="#index">Table Of Contents</A>
<H2>NAME</H2>
pnm - Netpbm superformat
<H2 id="description">DESCRIPTION</H2>
<P>The PNM format is just an abstraction of the PBM, PGM, and PPM
formats. I.e. the name "PNM" refers collectively to
PBM, PGM, and PPM.
<P>The name "PNM" is an acronym derived from "Portable
Any Map." This derivation makes more sense if you consider
it in the context of the other Netpbm format names: PBM, PGM, and PPM.
<P>The more general term "Netpbm format" refers to the PNM
formats plus PAM.
<p>PNM is principally used with <a href="index.html">Netpbm</a>.
<P>Note that besides being names of formats, PBM, PGM, PPM, and PNM
are also classes of programs. A PNM program can take PBM, PGM, or PPM
input. That's nothing special -- a PPM program can too. But a PNM
program can often produce multiple output formats as well, and a PNM
program can see the difference between PBM, PGM, and PPM input and
respond to each differently whereas a PPM program sees everything as
if it were PPM. This is discussed more in <a href="index.html">the
description of the netpbm programs</a>.
<P>"pnm" also appears in the names of the most general <a
href="libnetpbm.html">Netpbm library routines</a>, some of which aren't even
related to the PNM format.
<H2 id="seealso">SEE ALSO</H2>
<A HREF="ppm.html">ppm</A>,
<A HREF="pgm.html">pgm</A>,
<A HREF="pbm.html">pbm</A>,
<A HREF="pam.html">pam</A>,
<A HREF="directory.html">programs that process PNM</A>,
<A HREF="libnetpbm.html">libnetpbm</A>
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<H2 id="index">Table Of Contents</H2>
<UL>
<LI><A HREF="#description">DESCRIPTION</A>
<LI><A HREF="#seealso">SEE ALSO</A>
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