1Pnmtopnm User Manual(0)                                Pnmtopnm User Manual(0)
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NAME

6       pnmtopnm - copy a PNM image
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SYNOPSIS

9       pnmtopnm
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11       [pnmfile]
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DESCRIPTION

15       This program is part of Netpbm(1).
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17       pnmtopnm  simply copies a PNM image to Standard Output.  The output has
18       the same major PNM format (PBM, PGM, or PPM) and maxval as  the  input.
19       This  may  seem an unnecessary duplication of cat, but it lets you con‐
20       vert between the plain (ASCII) and raw (binary) subformats of PNM.  Use
21       the  -plain Netpbm common option to ensure the output is plain PNM, and
22       don't use -plain to ensure the output is raw PNM.  See
23        Common Options ⟨index.html#commonoptions⟩ .
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25       You don't normally need to convert between the PNM subformats,  because
26       any  program that uses the Netpbm library to read a PNM image will read
27       all of them directly.  But there are a lot of programs that  don't  use
28       the Netpbm library and understand only the raw format.  Plain format is
29       nice because it is human readable; people often use it  to  debug  pro‐
30       grams that process PNM images.
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32       pnmtopnm  is  really  just  another name for the program pamtopnm.  The
33       latter does the job because like any  Netpbm  program  that  takes  PAM
34       input  via the Netpbm programming library facilities, it also takes PNM
35       input.
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HISTORY

39       pnmtopnm was new in Netpbm 10.23  (July  2004).   It  obsoleted  pnmto‐
40       plainpnm,  which  specifically  did the conversion to plain PNM.  There
41       was no program to explicitly convert to raw PNM, but many  Netpbm  pro‐
42       grams can be made, with the right options, to be idempotent (i.e. to do
43       the same thing as pnmtopnm).
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45       Then David Jones realized that the existing pamtopnm already did every‐
46       thing that pnmtopnm did and more, so in Netpbm 10.27 (March 2005), pnm‐
47       topnm became simply an alternate name for pamtopnm.
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SEE ALSO

51       ppmtoppm(1) pgmtopgm(1) pamtopnm(1) pnm(1)
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55netpbm documentation             24 March 2005         Pnmtopnm User Manual(0)