libpnm

NAME

SYNOPSIS

#include <pnm.h>

DESCRIPTION

TYPES AND CONSTANTS

typedef ... xel;

Each xel contains three xelvals, each of which should contain only the values between 0 and PNM_MAXMAXVAL. pnm_pbmmaxval is the maxval used when a PNM program reads a PBM file. Normally it is 1; however, for some programs, a larger value gives better results.  

XEL MANIPULATIONS

xelval PNM_GET1( xel x

This macro extracts a single value from an xel, when you know it's from a PBM or PGM file. When it's from a PPM file, use PPM_GETR(), PPM_GETG(), and PPM_GETB().  

void PNM_ASSIGN1( xel x, xelval v

This 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().  

int PNM_EQUAL( xel x, xel y

This macro checks two xels for equality.  

int PNM_FORMAT_TYPE( int format

For distinguishing different file types.  

INITIALIZATION

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

All PNM programs must call this routine.  

MEMORY MANAGEMENT

xel** pnm_allocarray( int cols, int rows

Allocate an array of xels.  

xel* pnm_allocrow( int cols

Allocate a row of the given number of xels.  

void pnm_freearray( xel** xels, int rows

Free the array allocated with pnm_allocarray() containing the given number of rows.  

void pnm_freerow( xel* xelrow

Free a row of xels.  

READING FILES

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

Read the header from a PNM file, filling in the rows, cols, maxval and format variables.  

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

Read a row of xels into the xelrow array. Format, cols, and maxval were filled in by pnm_readpnminit().  

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

Read an entire anymap file into memory, returning the allocated array and filling in the rows, cols, maxval, and format variables. This function combines pnm_readpnminit(), pnm_allocarray() and pnm_readpnmrow(). Unlike the equivalent functions in PBM, PGM, and PPM, it returns the format so you can tell what type the file is.  

WRITING FILES

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

Write the header for a portable anymap file. Unlike the equivalent functions in PBM, PGM, and PPM, you have to specify the output type. The forceplain flag forces a plain-format file to be written, as opposed to a raw-format one.  

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

Write a row from a portable anymap.  

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

Write the header and all data for a portable anymap. This function combines pnm_writepnminit() and pnm_writepnmrow().  

MISCELLANEOUS

pnm_check() checks for the common file integrity error where the file is the wrong size to contain all the image data.

pnm_check() is identical to ppm_check().

FORMAT PROMOTION

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

Promote a row of xels from one maxval and format to a new set. Used when combining multiple anymaps of different types - just take the max of the maxvals and the max of the formats, and promote them all to that.  

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

Promote an entire anymap.  

XEL MANIPULATION

xel pnm_whitexel( xelval maxval, int format

Return a white or black xel for the given maxval and format.  

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

Invert an xel.  

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

Figure out an appropriate background xel based on this row.  

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

Figure out a background xel based on an entire anymap. This can do a slightly better job than pnm_backgroundxelrow().  

SEE ALSO

AUTHOR

Index

NAME

SYNOPSIS

#include <pnm.h>

DESCRIPTION

TYPES AND CONSTANTS

typedef ... xel;

XEL MANIPULATIONS

xelval PNM_GET1( xel x )

void PNM_ASSIGN1( xel x, xelval v )

int PNM_EQUAL( xel x, xel y )

int PNM_FORMAT_TYPE( int format )

INITIALIZATION

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

MEMORY MANAGEMENT

xel** pnm_allocarray( int cols, int rows )

xel* pnm_allocrow( int cols )

void pnm_freearray( xel** xels, int rows )

void pnm_freerow( xel* xelrow )

READING FILES

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 )

WRITING FILES

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 )

MISCELLANEOUS

FORMAT PROMOTION

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

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

XEL MANIPULATION

xel pnm_whitexel( 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 )

SEE ALSO

AUTHOR