in void calculate_edge_histogram, 1)IMPORTANT: corrected the index us…

…ed for img_buf, the +1 caused a out of array memory address to be looked up. Also it caused wrong calculations to take place arround the borders of the image 2)removed comments that were from an old version

sw/airborne/modules/computer_vision/lib/vision/edge_flow.c

@@ -122,9 +122,9 @@ void calculate_edge_histogram(struct image_t *img, int32_t edge_histogram[],
         sobel_sum = 0;
 
         for (c = -1; c <= 1; c++) {
-          idx = interlace * (image_width * y + (x + c)); // 2 for interlace
+          idx = interlace * (image_width * y + (x + c));
 
-          sobel_sum += Sobel[c + 1] * (int32_t)img_buf[idx + 1];
+          sobel_sum += Sobel[c + 1] * (int32_t)img_buf[idx];
         }
         sobel_sum = abs(sobel_sum);
         if (sobel_sum > edge_threshold) {
@@ -141,9 +141,9 @@ void calculate_edge_histogram(struct image_t *img, int32_t edge_histogram[],
         sobel_sum = 0;
 
         for (c = -1; c <= 1; c++) {
-          idx = interlace * (image_width * (y + c) + x); // 2 for interlace
+          idx = interlace * (image_width * (y + c) + x);
 
-          sobel_sum += Sobel[c + 1] * (int32_t)img_buf[idx + 1];
+          sobel_sum += Sobel[c + 1] * (int32_t)img_buf[idx];
         }
         sobel_sum = abs(sobel_sum);
         if (sobel_sum > edge_threshold) {