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- /* pgmbentley.c - read a portable graymap and smear it according to brightness
- **
- ** Copyright (C) 1990 by Wilson Bent (whb@hoh-2.att.com)
- **
- ** 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 <stdio.h>
- #include "pgm.h"
-
- int
- main( argc, argv )
- int argc;
- char* argv[];
- {
- FILE* ifp;
- gray maxval;
- gray** gin;
- gray** gout;
- int argn, rows, cols, row;
- register int brow, col;
- char* usage = "[pgmfile]";
-
-
- pgm_init( &argc, argv );
-
- argn = 1;
-
- if ( argn < argc )
- {
- ifp = pm_openr( argv[argn] );
- ++argn;
- }
- else
- ifp = stdin;
-
- if ( argn != argc )
- pm_usage( usage );
-
- gin = pgm_readpgm( ifp, &cols, &rows, &maxval );
- pm_close( ifp );
- gout = pgm_allocarray( cols, rows );
-
- #define N 4
- for ( row = 0; row < rows; ++row )
- for ( col = 0; col < cols; ++col )
- {
- brow = row + (int) (gin[row][col]) / N;
- if ( brow >= rows )
- brow = rows - 1;
- gout[brow][col] = gin[row][col];
- }
-
- pgm_writepgm( stdout, gout, cols, rows, maxval, 0 );
- pm_close( stdout );
- pgm_freearray( gout, rows );
-
- exit( 0 );
- }
-