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.TH pbm 3
.SH NAME
pbm - functions to support portable bitmap programs
.SH SYNOPSIS
.Ss
#include <pbm.h>
cc ... libpbm.a
.Se
.SH DESCRIPTION
.SS TYPES AND CONSTANTS
.Ss
typedef unsigned char bit;
#define PBM_WHITE 0
#define PBM_BLACK 1
.Se
Each
.IR bit
should contain only the values of
.IR white
or
.IR black .
.SS PBM MEMORY MANAGEMENT
.Ss
bit **pbm_allocarray(int cols, int rows)
.Se
Allocate an array of bits.
.Ss
bit *pbm_allocrow( int cols )
.Se
Allocate a row of the given number of bits.
.Ss
void pbm_freearray( bitrow, rows )
.Se
Free the array allocated with
.IR pbm_allocarray()
containing the given number
of rows.
.Ss
pbm_freerow( bitrow )
.Se
Free a row of bits.
.SS READING PBM FILES
.Ss
void
pbm_readpbminit( file, colsP, rowsP, formatP )
FILE *file;
int *colsP, *rowsP, *formatP;
.Se
Read the header from a pbm file, filling in the rows, cols and format
variables.
.Ss
void
pbm_readpbmrow( file, bitrow, cols, format )
FILE *file;
bit *bitrow;
int cols, format;
.Se
Read a row of bits into the bitrow array.
Format and cols were filled in by
.IR pbm_readpbminit() .
.Ss
bit **
pbm_readpbm( file, colsP, rowsP )
FILE *file;
int *colsP, *rowsP;
.Se
Read an entire bitmap file into memory, returning the allocated array and
filling in the rows and cols variables.
This function combines
.IR pbm_readpbminit() ,
.IR pbm_allocarray()
and
.IR pbm_readpbmrow() .
.SS WRITING PBM FILES
.Ss
void
pbm_writepbminit( file, cols, rows )
FILE *file;
int cols, rows;
.Se
Write the header for a portable bitmap file.
.Ss
void
pbm_writepbmrow( file, bitrow, cols )
FILE *file;
bit *bitrow;
int cols;
.Se
Write a row from a portable bitmap.
.Ss
void
pbm_writepbm( file, bits, cols, rows )
FILE *file;
bit **bits;
int cols, rows;
.Se
Write the header and all data for a portable bitmap.
This function combines
.IR pbm_writepbminit()
and
.IR pbm_writepbmrow() .
.SH "SEE ALSO"
pgm(3), ppm(3)
.SH AUTHOR
Manual by Tony Hansen.

Copyright (C) 1989 by Jef Poskanzer.

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.  This software is provided "as is" without express or
implied warranty.