Added fill_rect() for images.

dlib/image_transforms/draw.h

@@ -143,6 +143,29 @@ namespace dlib
 
     }
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename image_type,
+        typename pixel_type
+        >
+    void fill_rect (
+        image_type& img,
+        const rectangle& rect,
+        const pixel_type& pixel
+    )
+    {
+        rectangle area = rect.intersect(get_rect(img));
+
+        for (long r = area.top(); r <= area.bottom(); ++r)
+        {
+            for (long c = area.left(); c <= area.right(); ++c)
+            {
+                assign_pixel(img[r][c], pixel);
+            }
+        }
+    }
+
 // ----------------------------------------------------------------------------------------
 
 }

dlib/image_transforms/draw_abstract.h

@@ -32,6 +32,26 @@ namespace dlib
                   (i.e. it draws the line from (x1,y1) to (x2,y2) onto the image)
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename image_type,
+        typename pixel_type
+        >
+    void fill_rect (
+        image_type& img,
+        const rectangle& rect,
+        const pixel_type& pixel
+    );
+    /*!
+        requires
+            - pixel_traits<pixel_type> is defined
+        ensures
+            - fills the area defined by rect in the given image with the given pixel value.
+    !*/
+
+}
+
 // ----------------------------------------------------------------------------------------
 
 }