Create Subversion repository

git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@1 9d0c8265-081b-0410-96cb-a4ca84ce46f8

1 files changed, 91 insertions, 0 deletions

diff --git a/generator/pgmkernel.c b/generator/pgmkernel.c
new file mode 100644
index 00000000..b741d596
--- /dev/null
+++ b/generator/pgmkernel.c
@@ -0,0 +1,91 @@
+/* pgmkernel.c - generate a portable graymap convolution kernel
+**
+** Creates a Portable Graymap file containing a convolution filter
+** with max value = 255 and minimum value > 127 that can be used as a 
+** smoothing kernel for pnmconvol.
+**
+** Copyright (C) 1992 by Alberto Accomazzi, Smithsonian Astrophysical
+** Observatory.
+**
+** 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 <math.h>
+#include "pgm.h"
+#include "mallocvar.h"
+
+int
+main ( argc, argv )
+    int argc;
+    char *argv[];
+{
+    register    int i, j;
+    int     argn = 1, ixsize, iysize, maxval = 255;
+    double  fxsize = 0.0, fysize = 0.0, w = 6.0, kxcenter, kycenter, 
+        tmax = 0, *fkernel;
+    const char  *usage = "[-weight f] width [height]";
+
+    pgm_init( &argc, argv );
+
+    while ( argn < argc && argv[argn][0] == '-' && argv[argn][1] != '\0' )
+    {
+        if ( pm_keymatch( argv[argn], "-weight", 2 )) {
+            if (++argn >= argc)
+                pm_usage( usage );
+            else if (sscanf(argv[argn], "%lf", &w) != 1)
+                pm_usage( usage );
+        }
+        else
+            pm_usage( usage );
+        argn++;
+    }
+
+    if (argn == argc)
+        pm_usage( usage );
+    
+    if (sscanf(argv[argn], "%lf", &fxsize) != 1) 
+        pm_error( "error reading input kernel x size, (%s)\n", argv[argn]);
+
+    ++argn;
+    if (argn == argc - 1) {
+        if (sscanf(argv[argn], "%lf", &fysize) != 1)
+            pm_error( "error reading input kernel y size, (%s)\n", argv[argn]);
+    }
+    else if (argn == argc)
+        fysize = fxsize;
+    else
+        pm_usage( usage );
+
+    if (fxsize <= 1 || fysize <= 1)
+        pm_usage( usage );
+
+    kxcenter = (fxsize - 1) / 2.0;
+    kycenter = (fysize - 1) / 2.0;
+    ixsize = fxsize + 0.999;
+    iysize = fysize + 0.999;
+    MALLOCARRAY(fkernel, ixsize * iysize);
+    for (i = 0; i < iysize; i++) 
+        for (j = 0; j < ixsize; j++) {
+            fkernel[i*ixsize+j] = 1.0 / (1.0 + w * sqrt((double)
+                                                        (i-kycenter)*(i-kycenter)+
+                                                        (j-kxcenter)*(j-kxcenter)));
+            if (tmax < fkernel[i*ixsize+j])
+                tmax = fkernel[i*ixsize+j];
+        }
+
+    /* output PGM header + data (ASCII format only) */
+    printf("P2\n%d %d\n%d\n", ixsize, iysize, maxval);
+    
+    for (i = 0; i < iysize; i++, printf("\n"))
+        for (j = 0; j < ixsize; j++)
+            printf(" %3d", (int)(maxval * (fkernel[i*ixsize+j] / 
+                                           (2*tmax) + 0.5)));
+    
+    exit(0);
+}
+