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- /* ppmhist.c - read a portable pixmap and compute a color histogram
- **
- ** Copyright (C) 1989 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"
- #include "ppmcmap.h"
-
- #define MAXCOLORS 100000
-
- static int
- countcompare( ch1, ch2 )
- colorhist_vector ch1, ch2;
- {
- return ch2->value - ch1->value;
- }
-
- int
- main( argc, argv )
- int argc;
- char* argv[];
- {
- FILE* ifp;
- pixel** pixels;
- colorhist_vector chv;
- int argn, rows, cols, colors, i;
- pixval maxval;
- char* usage = "[-map] [ppmfile]";
- int map;
-
-
- ppm_init( &argc, argv );
-
- map = 0;
- argn = 1;
-
- while ( argn < argc && argv[argn][0] == '-' && argv[argn][1] != '\0' )
- {
- if( pm_keymatch( argv[argn], "-map", 2 ) )
- map = 1;
- else if( pm_keymatch( argv[argn], "-nomap", 2 ) )
- map = 0;
- else
- pm_usage( usage );
- ++argn;
- }
-
- if ( argn != argc )
- {
- ifp = pm_openr( argv[argn] );
- argn++;
- }
- else
- ifp = stdin;
-
- if ( argn != argc )
- pm_usage( usage );
-
- pixels = ppm_readppm( ifp, &cols, &rows, &maxval );
-
- pm_close( ifp );
-
- chv = ppm_computecolorhist( pixels, cols, rows, MAXCOLORS, &colors );
- if ( chv == (colorhist_vector) 0 )
- pm_error( "too many colors - try doing a ppmquant" );
-
- /* Sort by count. */
- qsort( (char*) chv, colors, sizeof(struct colorhist_item), countcompare );
-
- /* And print the histogram. */
- if( map )
- {
- printf("P3\n# color map\n%d 1\n%d\n", colors, maxval);
- printf( "# r g b \tlum\tcount\n" );
- printf( "#--- --- --- \t---\t-----\n" );
- }
- else
- {
- printf( " r g b \tlum\tcount\n" );
- printf( "--- --- ---\t---\t-----\n" );
- }
-
- for ( i = 0; i < colors; i++ )
- printf(
- "%3d %3d %3d%s\t%d\t%d\n", PPM_GETR(chv[i].color),
- PPM_GETG(chv[i].color), PPM_GETB(chv[i].color),
- (map ? " #" : ""),
- (int) ( PPM_LUMIN( chv[i].color ) + 0.5 ),
- chv[i].value );
-
- ppm_freecolorhist( chv );
-
- exit( 0 );
- }
-