Added some overloads of shrink_rect() and grow_rect() which

allow you to adjust the width and height independently.

dlib/geometry/rectangle.h

@@ -466,6 +466,28 @@ namespace dlib
         return shrink_rect(rect, -num);
     }
 
+// ----------------------------------------------------------------------------------------
+
+    inline const rectangle shrink_rect (
+        const rectangle& rect,
+        long width,
+        long height
+    )
+    {
+        return rectangle(rect.left()+width, rect.top()+height, rect.right()-width, rect.bottom()-height);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    inline const rectangle grow_rect (
+        const rectangle& rect,
+        long width,
+        long height
+    )
+    {
+        return shrink_rect(rect, -width, -height);
+    }
+
 // ----------------------------------------------------------------------------------------
 
     inline const rectangle translate_rect (

dlib/geometry/rectangle_abstract.h

@@ -491,6 +491,33 @@ namespace dlib
               (i.e. grows the given rectangle by expanding its border by num)
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    inline const rectangle shrink_rect (
+        const rectangle& rect,
+        long width,
+        long height
+    );
+    /*!
+        ensures
+            - returns rectangle(rect.left()+width, rect.top()+height, rect.right()-width, rect.bottom()-height)
+              (i.e. shrinks the given rectangle by shrinking its left and right borders by width
+              and its top and bottom borders by height. )
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+    inline const rectangle grow_rect (
+        const rectangle& rect,
+        long width,
+        long height
+    );
+    /*!
+        ensures
+            - return shrink_rect(rect, -width, -height)
+              (i.e. grows the given rectangle by expanding its border)
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     const rectangle translate_rect (