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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"
-
- void
- 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 );
- }
-