User manual for old pnm functions(3)			     Library Functions Manual			      User manual for old pnm functions(3)

NAME

       libpnm - libnetpbm functions to read and write PNM image files

SYNOPSIS

       #include <netpbm/pnm.h>

       void pnm_init( int *argcP, char *argv[] );

       xel ** pnm_allocarray( int cols, int rows);

       xel * pnm_allocrow( int cols);

       void pnm_freearray( xel **xels, int rows);

       void pnm_freerow( xel *xelrow);

       void pnm_readpnminit( FILE *fp, int *colsP, int *rowsP, xelval *maxvalP, int *formatP );

       void pnm_readpnmrow( FILE *fp, xel *xelrow, int cols, xelval maxval, int format );

       xel ** pnm_readpnm( FILE *fp, int *colsP, int *rowsP, xelval *maxvalP, int* formatP );

       void pnm_writepnminit( FILE *  fp , int cols, int rows, xelval maxval, int format, int forceplain);

       void pnm_writepnmrow( FILE *fp, xel *xelrow, int cols, xelval maxval, int format, int forceplain );

       void pnm_writepnm( FILE *fp, xel ** xels, int cols, int rows, xelval maxval, int format, int forceplain );

       void pnm_nextimage(FILE * file,
	 int * const eofP);

       void  pnm_check(  FILE  * file, const enum pm_check_type check_type, const int format, const int cols, const int rows, const xelval maxval,
       enum pm_check_code *retvalP);

       void pnm_promoteformatrow( xel *xelrow, int cols, xelval maxval, int format, xelval newmaxval, int newformat);

       void pnm_promoteformat( xel **xels, int cols, xelval maxval, int format, xelval newmaxval, int newformat);

       xel pnm_whitexel( xelval maxval, int format);

       xel pnm_blackxel( xelval maxval, int format);

       void pnm_invertxel( xel *x, xelval maxval, int format);

       xel pnm_backgroundxelrow( xel *xelrow, int cols, xelval maxval, int format);

       xel pnm_backgroundxel( xel **xels, int cols, int rows, xelval maxval, int format);

       typedef ... xelval;

       typedef ... xel;

       #define PNM_ASSIGN1(x,v) ...

       #define PNM_GET1(x) ...

       #define PNM_EQUAL(x,y) ...

       #define PNM_FORMAT_TYPE(format) ...

DESCRIPTION

       These library functions are part of Netpbm(1)

   TYPES AND CONSTANTS
       Each xel contains three xelvals, each of which should contain only the values between 0 and PNM_MAXMAXVAL, inclusive.

   XEL MANIPULATIONS
       The PNM_GET1 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
       PPM_GETR(), PPM_GETG(), and PPM_GETB().

       The  PNM_ASSIGN1  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
       PPM_ASSIGN.

       The PNM_EQUAL macro checks two xels for equality.  The PNM_FORMAT_TYPE 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.  PNM_FORMAT_TYPE does not work on the PAM format code.

       pnm_whitexel() and pnm_blackxel() return a white or black xel, respectively, for the given maxval and format.

       pnm_invertxel() inverts an xel.

   INITIALIZATION
       pnm_init() is identical to pm_proginit.

       pnm_init() is obsolete.	Use pm_proginit() instead.

   MEMORY MANAGEMENT
       pnm_allocarray() allocates space  for  an  array  of  xels.   pnm_freearray()  frees  an  array	space  allocated  by  pnm_allocarray()	or
       pnm_readpnm().

       pnm_allocrow() allocates space for a row of a PNM image.  pnm_freerow() frees it.

   READING PNM FILES
       pnm_readpnminit() is similar to pnm_readpaminit(), but reads only PNM images and has a different parameter list.

       pnm_readpnmrow()  is  similar to pnm_readpamrow() but only works on PNM images and has a different parameter list and returns the row as an
       array of xels instead of tuples.

       pnm_readpnm() is similar to pnm_readpam() except that it reads only PNM images and uses a different parameter list and returns an array	of
       rows such that pnm_readpnmrow() would return rather than such that pnm_readpamrow() would return.

   WRITING FILES
       pnm_writepnminit() is similar to pnm_writepaminit() except that it can write only a PNM header and has a different parameter list.

       forceplain  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 PNMformatspecification(5)

       pnm_writepnmrow() is similar to pnm_writepamrow() 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 forceplain	above.

       pnm_writepnm()  is  similar to pnm_writepam() 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 forceplain above.

   FORMAT PROMOTION
       pnm_promoteformatrow() 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.

       pnm_promoteformat() promotes an entire anymap.

   MISCELLANEOUS
       pnm_nextimage() positions a PNM input file to the next image in it (so that a subsequent pnm_readpnminit() reads its header).

       pnm_nextimage() is analogous to pbm_nextimage(), but works on PPM, PGM, and PBM files.

	pnm_check() is similar to pnm_checkpam() except it works only on PNM images.

       pnm_check() is identical to ppm_check().

       pnm_backgroundxelrow()  figures out an appropriate background xel based on the row of xels xelrow, which is cols xels wide, has maxval max-
       val, and represents an image with format format.

       This estimate works best when the row is the top or bottom row of the image.

       pnm_backgroundxel() does the same thing as pnm_backgroundxelrow(), except based on an entire image instead of just one row.  This tends	to
       do a slightly better job than pnmbackgroundxelrow().

SEE ALSO

       Libnetpbm(3) , LibnetpbmUser'sGuide(3) , LibnetpbmDirectory(1) , pbm(5) , pgm(5) , ppm(5) , pam(5) , libpbm(3) , libpgm(3) , libppm(3)

AUTHOR

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

netpbm documentation						 8 September 2007			      User manual for old pnm functions(3)