Data commit

Task/Bitmap-Histogram/C/bitmap-histogram-1.c

@@ -0,0 +1,7 @@
+typedef unsigned int histogram_t;
+typedef histogram_t *histogram;
+
+#define GET_LUM(IMG, X, Y) ( (IMG)->buf[ (Y) * (IMG)->width + (X)][0] )
+
+histogram get_histogram(grayimage im);
+luminance histogram_median(histogram h);

Task/Bitmap-Histogram/C/bitmap-histogram-2.c

@@ -0,0 +1,20 @@
+histogram get_histogram(grayimage im)
+{
+   histogram t;
+   unsigned int x, y;
+
+   if ( im == NULL ) return NULL;
+   t = malloc( sizeof(histogram_t)*256 );
+   memset(t, 0, sizeof(histogram_t)*256 );
+   if (t!=NULL)
+   {
+       for(x=0; x < im->width; x++ )
+       {
+         for(y=0; y < im->height; y++ )
+         {
+            t[ GET_LUM(im, x, y) ]++;
+         }
+       }
+   }
+   return t;
+}

Task/Bitmap-Histogram/C/bitmap-histogram-3.c

@@ -0,0 +1,19 @@
+luminance histogram_median(histogram h)
+{
+    luminance From, To;
+    unsigned int Left, Right;
+
+    From = 0; To = (1 << (8*sizeof(luminance)))-1;
+    Left = h[From]; Right = h[To];
+
+    while( From != To )
+    {
+       if ( Left < Right )
+       {
+          From++; Left += h[From];
+       } else {
+          To--; Right += h[To];
+       }
+    }
+    return From;
+}

Task/Bitmap-Histogram/C/bitmap-histogram-4.c

@@ -0,0 +1,50 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "imglib.h"
+
+/* usage example */
+
+#define BLACK 0,0,0
+#define WHITE 255,255,255
+
+int main(int argc, char **argv)
+{
+    image color_img;
+    grayimage g_img;
+    histogram h;
+    luminance T;
+    unsigned int x, y;
+
+    if ( argc < 2 )
+    {
+       fprintf(stderr, "histogram FILE\n");
+       exit(1);
+    }
+    color_img = read_image(argv[1]);
+    if ( color_img == NULL ) exit(1);
+    g_img = tograyscale(color_img);
+    h = get_histogram(g_img);
+    if ( h != NULL )
+    {
+          T = histogram_median(h);
+
+          for(x=0; x < g_img->width; x++)
+          {
+            for(y=0; y < g_img->height; y++)
+            {
+               if ( GET_LUM(g_img,x,y) < T )
+               {
+                   put_pixel_unsafe(color_img, x, y, BLACK);
+               } else {
+                   put_pixel_unsafe(color_img, x, y, WHITE);
+               }
+            }
+          }
+          output_ppm(stdout, color_img);
+          /* print_jpg(color_img, 90); */
+          free(h);
+    }
+
+    free_img((image)g_img);
+    free_img(color_img);
+}