man > pnm(5)

The PNM Format(5)                        File Formats Manual                       The PNM Format(5)

NAME
       pnm - Netpbm superformat


DESCRIPTION
       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.

       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.

       The more general term "Netpbm format" refers to the PNM formats plus PAM.

       PNM is principally used with Netpbm(1).

       Note  that  besides  being  names of formats, PBM, PGM, PPM, and PNM are also classes of pro‐
       grams.  A PNM program can take PBM, PGM, or PPM input.  That's nothing special -- a PPM  pro‐
       gram 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 differ‐
       ently whereas a PPM program sees everything as if it were PPM.  This is discussed more in the
       description of the netpbm programs" (1).

       "pnm" also appears in the names of the most general Netpbm library routines(1), some of which
       aren't even related to the PNM format.


INTERNET MEDIA TYPE
       No Internet Media Type (aka MIME type, content type) for PNM has  been  registered  with  the
       IANA, but the value image/x-portable-anymap is conventional.

       Note  that  there  are also conventional Internet Media Types for each of the PNM subformats.
       The recommended practice is to use those in preference to the PNM code when it is  convenient
       to do so.


FILE NAME
       There  are no requirements on the name of a PNM file, but the convention is to use the suffix
       "pbm", "pgm", or "ppm", depending on the particular subformat, or "pnm" if it is  not  conve‐
       nient to distinguish the subformats.



SEE ALSO
       ppm(1), pgm(1), pbm(1), pam(1), programs that process PNM(1), libnetpbm(1)

DOCUMENT SOURCE
       This  manual  page  was  generated by the Netpbm tool 'makeman' from HTML source.  The master
       documentation is at

              http://netpbm.sourceforge.net/doc/pnm.html

netpbm documentation                      27 November 2013                         The PNM Format(5)