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- /* ppmchange.c - change a given color to another
- **
- ** Copyright (C) 1991 by Wilson H. Bent, Jr.
- **
- ** 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* ifp;
- int argn, format, row;
- register int col;
- int rows, cols;
- pixel* prow;
- pixel color0, color1;
- pixval maxval;
- char* usage = "<oldcolor> <newcolor> [ppmfile]";
-
- ppm_init( &argc, argv );
-
- argn = 1;
-
- if ( argn == argc )
- pm_usage( usage );
- color0 = ppm_parsecolor( argv[argn], PPM_MAXMAXVAL );
- ++argn;
- color1 = ppm_parsecolor( argv[argn], PPM_MAXMAXVAL );
- ++argn;
-
- if ( argn != argc )
- {
- ifp = pm_openr( argv[argn] );
- ++argn;
- }
- else
- ifp = stdin;
-
- if ( argn != argc )
- pm_usage( usage );
-
- ppm_readppminit( ifp, &cols, &rows, &maxval, &format );
- ppm_writeppminit( stdout, cols, rows, maxval, 0 );
- prow = ppm_allocrow( cols );
-
- /* Scan for the desired color */
- for ( row = 0; row < rows; ++row )
- {
- ppm_readppmrow( ifp, prow, cols, maxval, format );
- for ( col = 0; col < cols; ++col )
- if ( PPM_EQUAL( prow[col], color0 ) )
- PPM_ASSIGN( prow[col],
- PPM_GETR( color1 ),
- PPM_GETG( color1 ),
- PPM_GETB( color1 ) );
- ppm_writeppmrow( stdout, prow, cols, maxval, 0 );
- }
-
- pm_close( ifp );
-
- exit( 0 );
- }
-