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/* rgb3toppm - combine three portable graymaps into one portable pixmap
**
** Copyright (C) 1991 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.
*/
#include "ppm.h"
int
main( argc, argv )
int argc;
char* argv[];
{
FILE* rfd;
FILE* gfd;
FILE* bfd;
gray* rrow;
gray* rP;
gray* grow;
gray* gP;
gray* brow;
gray* bP;
pixel* pixelrow;
register pixel* pP;
int rows, cols, trows, tcols, row, col;
gray rmaxval, gmaxval, bmaxval;
int rformat, gformat, bformat;
pixval pmaxval;
ppm_init( &argc, argv );
if ( argc != 4 )
pm_usage( "<red pgmfile> <green pgmfile> <blue pgmfile> " );
rfd = pm_openr( argv[1] );
gfd = pm_openr( argv[2] );
bfd = pm_openr( argv[3] );
pgm_readpgminit( rfd, &cols, &rows, &rmaxval, &rformat );
pgm_readpgminit( gfd, &tcols, &trows, &gmaxval, &gformat );
if ( tcols != cols || trows != rows )
pm_error( "all three graymaps must be the same size" );
pgm_readpgminit( bfd, &tcols, &trows, &bmaxval, &bformat );
if ( tcols != cols || trows != rows )
pm_error( "all three graymaps must be the same size" );
pmaxval = rmaxval;
if ( gmaxval > pmaxval ) pmaxval = gmaxval;
if ( bmaxval > pmaxval ) pmaxval = bmaxval;
rrow = pgm_allocrow( cols );
grow = pgm_allocrow( cols );
brow = pgm_allocrow( cols );
ppm_writeppminit( stdout, cols, rows, pmaxval, 0 );
pixelrow = ppm_allocrow( cols );
for ( row = 0; row < rows; row++ )
{
pgm_readpgmrow( rfd, rrow, cols, rmaxval, rformat );
pgm_readpgmrow( gfd, grow, cols, gmaxval, gformat );
pgm_readpgmrow( bfd, brow, cols, bmaxval, bformat );
for ( col = 0, rP = rrow, gP = grow, bP = brow, pP = pixelrow;
col < cols;
++col, ++rP, ++gP, ++bP, ++pP )
{
if ( rmaxval != pmaxval ) *rP = (int) *rP * pmaxval / rmaxval;
if ( gmaxval != pmaxval ) *gP = (int) *gP * pmaxval / gmaxval;
if ( bmaxval != pmaxval ) *bP = (int) *bP * pmaxval / bmaxval;
PPM_ASSIGN( *pP, *rP, *gP, *bP );
}
ppm_writeppmrow( stdout, pixelrow, cols, pmaxval, 0 );
}
pm_close( rfd );
pm_close( gfd );
pm_close( bfd );
pm_close( stdout );
exit( 0 );
}
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