\
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.TH "User manual for old pnm functions" 3 "8 September 2007" "netpbm documentation"

.SH NAME
libpnm - libnetpbm functions to read and write PNM image files

.UN synopsis
.SH SYNOPSIS

\fB#include <netpbm/pnm.h>\fP
.PP
\fBvoid pnm_init(\fP
\fBint *\fP\fIargcP\fP\fB,\fP
\fBchar *\fP\fIargv\fP\fB[]\fP
\fB);\fP
.PP
\fBxel ** pnm_allocarray(\fP
\fBint \fP\fIcols\fP\fB,\fP
\fBint \fP\fIrows\fP\fB);\fP
.PP
\fBxel * pnm_allocrow(\fP
\fBint \fP\fIcols\fP\fB);\fP
.PP
\fBvoid pnm_freearray(\fP
\fBxel **\fP\fIxels\fP\fB,\fP
\fBint \fP\fIrows\fP\fB);\fP
.PP
\fBvoid pnm_freerow(\fP
\fBxel *\fP\fIxelrow\fP\fB);\fP
.PP
\fBvoid pnm_readpnminit( \fP
\fBFILE *\fP\fIfp\fP\fB,\fP
\fBint *\fP\fIcolsP\fP\fB,\fP
\fBint *\fP\fIrowsP\fP\fB,\fP
\fBxelval *\fP\fImaxvalP\fP\fB,\fP
\fBint *\fP\fIformatP\fP\fB );\fP
.PP
\fBvoid pnm_readpnmrow( \fP
\fBFILE *\fP\fIfp\fP\fB,\fP
\fBxel *\fP\fIxelrow\fP\fB,\fP
\fBint \fP\fIcols\fP\fB,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB );\fP
.PP
\fBxel ** pnm_readpnm( \fP
\fBFILE *\fP\fIfp\fP\fB,\fP
\fBint *\fP\fIcolsP\fP\fB,\fP
\fBint *\fP\fIrowsP\fP\fB,\fP
\fBxelval *\fP\fImaxvalP\fP\fB, int\fP\fI*\fP\fB formatP \fP\fI);\fP
.PP
\fBvoid pnm_writepnminit( \fP
\fBFILE *  fp , \fP
\fBint \fP\fIcols\fP\fB,\fP
\fBint \fP\fIrows\fP\fB,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB,\fP
\fBint \fP\fIforceplain\fP\fB);\fP
.PP
\fBvoid pnm_writepnmrow( \fP
\fBFILE *\fP\fIfp\fP\fB,\fP
\fBxel *\fP\fIxelrow\fP\fB,\fP
\fBint cols\fP\fI,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB,\fP
\fBint \fP\fIforceplain\fP\fB );\fP
.PP
\fBvoid pnm_writepnm( \fP
\fBFILE *\fP\fIfp\fP\fB,\fP
\fBxel ** \fP\fIxels\fP\fB,\fP
\fBint \fP\fIcols\fP\fB,\fP
\fBint \fP\fIrows\fP\fB,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB,\fP
\fBint \fP\fIforceplain\fP\fB );\fP
.PP
\fBvoid pnm_nextimage(\fP\fBFILE *\fP \fIfile\fP\fB,\fP
  \fBint * const\fP \fIeofP\fP\fB);\fP
.PP
\fBvoid pnm_check(\fP
\fBFILE * \fP\fIfile\fP\fB,\fP
\fBconst enum pm_check_type \fP\fIcheck_type\fP\fB,\fP
\fBconst int \fP\fIformat\fP\fB,\fP
\fBconst int \fP\fIcols\fP\fB,\fP
\fBconst int \fP\fIrows\fP\fB,\fP
\fBconst xelval \fP\fImaxval\fP\fB,\fP
\fBenum pm_check_code *\fP\fIretvalP\fP\fB);\fP
.PP
\fBvoid pnm_promoteformatrow( \fP
\fBxel *\fP\fIxelrow\fP\fB,\fP
\fBint \fP\fIcols\fP\fB,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB,\fP
\fBxelval \fP\fInewmaxval\fP\fB,\fP
\fBint \fP\fInewformat\fP\fB);\fP
.PP
\fBvoid pnm_promoteformat( \fP
\fBxel **\fP\fIxels\fP\fB,\fP
\fBint \fP\fIcols\fP\fB,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB,\fP
\fBxelval \fP\fInewmaxval\fP\fB,\fP
\fBint \fP\fInewformat\fP\fB);\fP
.PP
\fBxel pnm_whitexel( \fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB);\fP
.PP
\fBxel pnm_blackxel( \fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB);\fP
.PP
\fBvoid pnm_invertxel( \fP
\fBxel *\fP\fIx\fP\fB,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB);\fP
.PP
\fBxel pnm_backgroundxelrow( \fP
\fBxel *\fP\fIxelrow\fP\fB,\fP
\fBint \fP\fIcols\fP\fB,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB);\fP
.PP
\fBxel pnm_backgroundxel( \fP
\fBxel **\fP\fIxels\fP\fB,\fP
\fBint \fP\fIcols\fP\fB,\fP
\fBint \fP\fIrows\fP\fB,\fP
\fBxelval \fP\fImaxval\fP\fB,\fP
\fBint \fP\fIformat\fP\fB);\fP
.PP
\fBtypedef ... xelval;\fP
.PP
\fBtypedef ... xel;\fP
.PP
\fB#define \fP
\fBPNM_ASSIGN1(\fP\fIx\fP\fB,\fP\fIv\fP\fB)\fP
\fB...\fP
.PP
\fB#define \fP
\fBPNM_GET1(\fP\fIx\fP\fB)\fP
\fB...\fP
.PP
\fB#define \fP
\fBPNM_EQUAL(\fP\fIx\fP\fB,\fP\fIy\fP\fB)\fP
\fB...\fP
.PP
\fB#define \fP
\fBPNM_FORMAT_TYPE(\fP\fIformat\fP\fB)\fP
\fB...\fP

.UN description
.SH DESCRIPTION
.PP
These library functions are part of
.BR Netpbm (1)
.


.UN types
.SS TYPES AND CONSTANTS
.PP
Each \fBxel\fP contains three \fBxelval\fPs, each of which should
contain only the values between \fB0\fP and \fBPNM_MAXMAXVAL\fP,
inclusive. 

.UN xel
.SS XEL MANIPULATIONS
.PP
The \fBPNM_GET1\fP macro extracts a single value from an xel, when
ou know it's from a PBM or PGM file.  When it's from a PPM file, use
\fBPPM_GETR()\fP, \fBPPM_GETG()\fP, and \fBPPM_GETB()\fP.
.PP
The \fBPNM_ASSIGN1\fP macro assigns a single value to an xel, when
you know it's from a PBM or PGM file.  When it's from a PPM file, use
\fBPPM_ASSIGN\fP.

The \fBPNM_EQUAL\fP macro checks two xels for equality.  The
\fBPNM_FORMAT_TYPE\fP macro computes a
format type code from a format code.  The format types are PBM, PGM,
PPM, and PAM.  But note that PBM, PGM, and PPM each are two different
formats: a plain one and a raw one.  So there are four format types,
but seven formats.  \fBPNM_FORMAT_TYPE\fP does not work on the PAM
format code.

\fBpnm_whitexel()\fP and \fBpnm_blackxel()\fP return a white or
black xel, respectively, for the given \fImaxval\fP and
\fIformat\fP.
.PP
\fBpnm_invertxel()\fP inverts an xel.

.UN initialization
.SS INITIALIZATION
.PP
\fBpnm_init()\fP is obsolete (at least since Netpbm 9.25 (March 2002)).
Use 
.UR libpm.html#initialization
\fBpm_proginit()\fP
.UE
\& instead.
.PP
\fBpnm_init()\fP is identical to \fBpm_proginit\fP.

.UN memorymanagement
.SS MEMORY MANAGEMENT
.PP
\fBpnm_allocarray()\fP allocates space for an array of xels.
\fBpnm_freearray()\fP frees an array space allocated by
\fBpnm_allocarray()\fP or \fBpnm_readpnm()\fP.
.PP
\fBpnm_allocrow()\fP allocates space for a row of a PNM image.
\fBpnm_freerow()\fP frees it.


.UN reading
.SS READING PNM FILES
.PP
\fBpnm_readpnminit()\fP is similar to \fBpnm_readpaminit()\fP,
but reads only PNM images and has a different parameter list.
.PP
\fBpnm_readpnmrow()\fP is similar to \fBpnm_readpamrow()\fP
but only works on PNM images and has a different parameter list and returns
the row as an array of xels instead of tuples.
.PP
\fBpnm_readpnm()\fP is similar to \fBpnm_readpam()\fP except that
it reads only PNM images and uses a different parameter list and
returns an array of rows such that \fBpnm_readpnmrow()\fP would
return rather than such that \fBpnm_readpamrow()\fP would return.


.UN writing
.SS WRITING FILES
.PP
\fBpnm_writepnminit()\fP is similar to \fBpnm_writepaminit()\fP
except that it can write only a PNM header and has a different
parameter list.
.PP
\fIforceplain\fP is a binary value.  True (nonzero) means to write
the image in the plain (ASCII) version of the selected format.  False
(zero) means to write it in the raw (binary) version of the selected
format.  See
.BR PNM format specification (5)
.
.PP
\fBpnm_writepnmrow()\fP is similar to \fBpnm_writepamrow()\fP
except that it works only on PNM images and has a different parameter
list and takes an array of xels instead of an array of tuples.  See
the description of \fIforceplain \fP above.
.PP
\fBpnm_writepnm()\fP is similar to \fBpnm_writepam()\fP except
that it works only on PNM image, has a different parameter list, and
takes an array of rows of xels instead of an array of rows of tuples.
See the description of \fIforceplain\fP above.


.UN promotion
.SS FORMAT PROMOTION

\fBpnm_promoteformatrow()\fP promotes a row of xels from one maxval
and format to a new set.  Use this when you are combining multiple
anymaps of different types - just take the maximum of the maxvals and
the maximum of the formats, and promote them all to that.
.PP
\fBpnm_promoteformat()\fP promotes an entire anymap.

.UN miscellaneous
.SS MISCELLANEOUS
.PP
\fBpnm_nextimage()\fP positions a PNM input file to the next image
in it (so that a subsequent \fBpnm_readpnminit()\fP reads its
header).
.PP
\fBpnm_nextimage()\fP is analogous to \fBpbm_nextimage()\fP, but
works on PPM, PGM, and PBM files.
.PP
 \fBpnm_check()\fP is similar to \fBpnm_checkpam()\fP except it
works only on PNM images.
.PP
\fBpnm_check()\fP is identical to \fBppm_check()\fP.
.PP
\fBpnm_backgroundxelrow()\fP figures out an appropriate background
xel based on the row of xels \fIxelrow\fP, which is \fIcols\fP xels
wide, has maxval \fImaxval\fP, and represents an image with format
\fIformat\fP.
.PP
This estimate works best when the row is the top or bottom row of
the image.
.PP
\fBpnm_backgroundxel()\fP does the same thing as
\fBpnm_backgroundxelrow()\fP, except based on an entire image instead
of just one row.  This tends to do a slightly better job than
\fBpnmbackgroundxelrow()\fP.

.UN seealso
.SH SEE ALSO
.BR Libnetpbm (3)
,
.BR Libnetpbm User's Guide (3)
,
.BR Libnetpbm Directory (1)
,
.BR pbm (5)
,
.BR pgm (5)
,
.BR ppm (5)
,
.BR pam (5)
,
.BR libpbm (3)
,
.BR libpgm (3)
,
.BR libppm (3)


.UN author
.SH AUTHOR

Copyright (C) 1989, 1991 by Tony Hansen and Jef Poskanzer.