Create Subversion repository

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

1 files changed, 80 insertions, 0 deletions

diff --git a/converter/other/pbmtopgm.c b/converter/other/pbmtopgm.c
new file mode 100644
index 00000000..69b20fb2
--- /dev/null
+++ b/converter/other/pbmtopgm.c
@@ -0,0 +1,80 @@
+/* pbmtopgm.c - convert PBM to PGM by totalling pixels over sample area
+ * AJCD 12/12/90
+ */
+
+#include <stdio.h>
+
+#include "pm_c_util.h"
+#include "pgm.h"
+
+int
+main(int argc, char *argv[]) {
+
+    gray *outrow, maxval;
+    int right, left, down, up;
+    bit **inbits;
+    int rows, cols;
+    FILE *ifd;
+    int row;
+    int width, height;
+    const char * const usage = "<w> <h> [pbmfile]";
+   
+
+    pgm_init( &argc, argv );
+
+    if (argc > 4 || argc < 3)
+        pm_usage(usage);
+
+    width = atoi(argv[1]);
+    height = atoi(argv[2]);
+    if (width < 1 || height < 1)
+        pm_error("width and height must be > 0");
+    left=width/2; right=width-left;
+    up=width/2; down=height-up;
+
+    if (argc == 4)
+        ifd = pm_openr(argv[3]);
+    else
+        ifd = stdin ;
+
+    inbits = pbm_readpbm(ifd, &cols, &rows) ;
+    
+    if (width > cols)
+        pm_error("You specified a sample width (%u columns) which is greater "
+                 "than the image width (%u columns)", height, rows);
+    if (height > rows)
+        pm_error("You specified a sample height (%u rows) which is greater "
+                 "than the image height (%u rows)", height, rows);
+
+    outrow = pgm_allocrow(cols) ;
+    maxval = MIN(PGM_OVERALLMAXVAL, width*height);
+    pgm_writepgminit(stdout, cols, rows, maxval, 0) ;
+
+    for (row = 0; row < rows; row++) {
+        int const t = (row > up) ? (row-up) : 0;
+        int const b = (row+down < rows) ? (row+down) : rows;
+        int const onv = height - (t-row+up) - (row+down-b);
+        unsigned int col;
+        for (col = 0; col < cols; col++) {
+            int const l = (col > left) ? (col-left) : 0;
+            int const r = (col+right < cols) ? (col+right) : cols;
+            int const onh = width - (l-col+left) - (col+right-r);
+            int value;
+            int x;
+
+            value = 0;  /* initial value */
+
+            for (x = l; x < r; ++x) {
+                int y;
+                for (y = t; y < b; ++y)
+                    if (inbits[y][x] == PBM_WHITE) 
+                        ++value;
+            }
+            outrow[col] = maxval*value/(onh*onv);
+        }
+        pgm_writepgmrow(stdout, outrow, cols, maxval, 0) ;
+    }
+    pm_close(ifd);
+
+    return 0;
+}