diff --git a/includes/image.inc b/includes/image.inc
index a6e7ab9..e30a338 100644
--- a/includes/image.inc
+++ b/includes/image.inc
@@ -290,12 +290,12 @@ function image_resize(stdClass $image, $width, $height) {
  *   An image object returned by image_load().
  * @param $degrees
  *   The number of (clockwise) degrees to rotate the image.
- * @param int $background
- *   (optional) A 24 bit or 32 bit ARGB value specifying the background color
- *   to use for the uncovered area of the image after the rotation (for
- *   example, 0 for black, 16711935 for fuchsia, and 16777215 for white). For
- *   images that support transparency, this will default to transparent.
- *   Otherwise it will be white.
+ * @param $background
+ *   An hexadecimal integer specifying the background color to use for the
+ *   uncovered area of the image after the rotation. E.g. 0x000000 for black,
+ *   0xff00ff for magenta, and 0xffffff for white. For images that support
+ *   transparency, this will default to transparent. Otherwise it will
+ *   be white.
  *
  * @return
  *   TRUE on success, FALSE on failure.
@@ -431,23 +431,5 @@ function image_save(stdClass $image, $destination = NULL) {
 }
 
 /**
- * Converts a 24 bit RGB or 32 bit ARGB value to an RGBA array.
- *
- * @param int $argb
- *   The color code to convert.
- *
- * @return array
- *   An array containing the values for 'red', 'green', 'blue', and 'alpha'.
- */
-function image_dec_to_rgba($argb) {
-  return array(
-    'red' => $argb >> 16 & 0xFF,
-    'green' => $argb >> 8 & 0xFF,
-    'blue' => $argb & 0xFF,
-    'alpha' => $argb >> 24 & 0xFF,
-  );
-}
-
-/**
  * @} End of "defgroup image".
  */
diff --git a/modules/simpletest/tests/image.test b/modules/simpletest/tests/image.test
index cb346c1..3b816f1 100644
--- a/modules/simpletest/tests/image.test
+++ b/modules/simpletest/tests/image.test
@@ -448,6 +448,7 @@ class ImageToolkitGdTestCase extends DrupalWebTestCase {
         $correct_dimensions_object = TRUE;
         $correct_colors = TRUE;
 
+        // Check the real dimensions of the image first.
         if (imagesy($image->resource) != $values['height'] || imagesx($image->resource) != $values['width']) {
           $correct_dimensions_real = FALSE;
         }
diff --git a/modules/system/image.gd.inc b/modules/system/image.gd.inc
index 6552a37..3d0797e 100644
--- a/modules/system/image.gd.inc
+++ b/modules/system/image.gd.inc
@@ -98,12 +98,12 @@ function image_gd_resize(stdClass $image, $width, $height) {
  *   $image->info['height'] values will be modified by this call.
  * @param $degrees
  *   The number of (clockwise) degrees to rotate the image.
- * @param int $background
- *   (optional) A 24 bit or 32 bit ARGB value specifying the background color
- *   to use for the uncovered area of the image after the rotation (for
- *   example, 0 for black, 16711935 for fuchsia, and 16777215 for white). For
- *   images that support transparency, this will default to transparent.
- *   Otherwise it will be white.
+ * @param $background
+ *   An hexadecimal integer specifying the background color to use for the
+ *   uncovered area of the image after the rotation. E.g. 0x000000 for black,
+ *   0xff00ff for magenta, and 0xffffff for white. For images that support
+ *   transparency, this will default to transparent. Otherwise it will
+ *   be white.
  * @return
  *   TRUE or FALSE, based on success.
  *
@@ -121,13 +121,23 @@ function image_gd_rotate(stdClass $image, $degrees, $background = NULL) {
   // angle to a positive one between 0 and 360 degrees.
   $degrees -= floor($degrees / 360) * 360;
 
+  // Convert the hexadecimal background value to a RGBA array.
   if (isset($background)) {
-    $background = image_dec_to_rgba($background);
-    $background['alpha'] = 0;
+    $background = array(
+      'red' => $background >> 16 & 0xFF,
+      'green' => $background >> 8 & 0xFF,
+      'blue' => $background & 0xFF,
+      'alpha' => 0,
+    );
   }
   else {
     // Background color is not specified: use transparent white as background.
-    $background = array('red' => 255, 'green' => 255, 'blue' => 255, 'alpha' => 127);
+    $background = array(
+      'red' => 255,
+      'green' => 255,
+      'blue' => 255,
+      'alpha' => 127
+    );
   }
 
   // Store the color index for the background as that is what GD uses.