1 files changed, 99 insertions, 0 deletions
diff --git a/converter/ppm/ppmtorgb3.c b/converter/ppm/ppmtorgb3.c
new file mode 100644
index 00000000..21d3346a
--- /dev/null
+++ b/converter/ppm/ppmtorgb3.c
@@ -0,0 +1,99 @@
+/* ppmtorgb3.c - separate a portable pixmap into three portable graymaps
+**
+** 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 <string.h>
+#include "ppm.h"
+#include "pgm.h"
+
+int
+main( argc, argv )
+    int argc;
+    char* argv[];
+    {
+    FILE* ifp;
+    FILE* redfile;
+    FILE* grnfile;
+    FILE* blufile;
+    const char* basename;
+    char filename[100];
+    char* cp;
+    pixel* pixelrow;
+    register pixel* pP;
+    gray* grayrow;
+    register gray* gP;
+    int rows, cols, format, row;
+    register int col;
+    pixval maxval;
+
+
+    ppm_init( &argc, argv );
+
+    if ( argc > 2 )
+	pm_usage( "[ppmfile]" );
+
+    if ( argc == 2 )
+	{
+	ifp = pm_openr( argv[1] );
+	basename = argv[1];
+	cp = strrchr( basename, '.' );
+	if ( cp != NULL )
+	    *cp = '\0';
+	}
+    else
+	{
+	ifp = stdin;
+	basename = "noname";
+	}
+
+    ppm_readppminit( ifp, &cols, &rows, &maxval, &format );
+    pixelrow = ppm_allocrow( cols );
+    (void) strcpy( filename, basename );
+    (void) strcat( filename, ".red" );
+    redfile = pm_openw( filename );
+    pgm_writepgminit( redfile, cols, rows, (gray) maxval, 0 );
+    (void) strcpy( filename, basename );
+    (void) strcat( filename, ".grn" );
+    grnfile = pm_openw( filename );
+    pgm_writepgminit( grnfile, cols, rows, (gray) maxval, 0 );
+    (void) strcpy( filename, basename );
+    (void) strcat( filename, ".blu" );
+    blufile = pm_openw( filename );
+    pgm_writepgminit( blufile, cols, rows, (gray) maxval, 0 );
+    grayrow = pgm_allocrow( cols );
+
+    for ( row = 0; row < rows; ++row )
+	{
+	ppm_readppmrow( ifp, pixelrow, cols, maxval, format );
+
+	for ( col = 0, pP = pixelrow, gP = grayrow; col < cols;
+	      ++col, ++pP, ++gP )
+	    *gP = (gray) PPM_GETR( *pP );
+	pgm_writepgmrow( redfile, grayrow, cols, maxval, 0 );
+
+	for ( col = 0, pP = pixelrow, gP = grayrow; col < cols;
+	      ++col, ++pP, ++gP )
+	    *gP = (gray) PPM_GETG( *pP );
+	pgm_writepgmrow( grnfile, grayrow, cols, maxval, 0 );
+
+	for ( col = 0, pP = pixelrow, gP = grayrow; col < cols;
+	      ++col, ++pP, ++gP )
+	    *gP = (gray) PPM_GETB( *pP );
+	pgm_writepgmrow( blufile, grayrow, cols, maxval, 0 );
+	}
+
+    pm_close( ifp );
+    pm_close( redfile );
+    pm_close( blufile );
+    pm_close( grnfile );
+
+    exit( 0 );
+    }