diff -Naur old/image_resize_filter.module new/image_resize_filter.module
--- old/image_resize_filter.module	2011-12-13 13:39:46.385723800 +0000
+++ new/image_resize_filter.module	2011-12-15 15:01:34.894462700 +0000
@@ -100,9 +100,30 @@
     'image_resize_filter_form' => array(
       'arguments' => array('form' => NULL),
     ),
+	// Patch by AMS -- Register the theme_ ... function
+	'image_resize_filter_scale_factor' => array(
+      'arguments' => array('height' => NULL, 'width' => NULL),
+    ),
+	
   );
 }
 
+//  Patch by AMS -- Null version of Hook.  A Scale Factor of 1 is ignored.  
+/**
+ * Implementation of theme_image_resize_filter_scale_factor().
+ *
+ * Allows the Theme to apply a further scaling of images, 
+ * e.g. to reduce the size for small mobile phone screens.
+ *
+ * Parameters	Passes Height and Width of image (in pixels) to allow the theme
+ *				to adjust the scaling to size of original (if required)
+ * Return		A numeric (float) value by which the height and width will be multiplied.
+ *				E.g. 1 = no change.  0.5 = half size.
+ */
+ function theme_image_resize_filter_scale_factor ($height, $width) {
+	return 1;
+}
+
 /**
  * Implementation of hook_file_download().
  */
@@ -364,6 +385,7 @@
     // If this is a remote image, retreive it to check its size.
     if ($location == 'remote') {
       $result = drupal_http_request($src);
+drupal_set_message($result->code);
       if ($result->code == 200) {
         $tmp_file = tempnam(file_directory_temp(), 'image_resize_filter_');
         $handle = fopen($tmp_file, 'w');
@@ -400,6 +422,17 @@
       $ratio = $actual_width/$actual_height;
       $attributes['width'] = (int) round($ratio * $attributes['height']);
     }
+
+	// Patch by AMS 
+	// Now the target size is established, call a theme function hook to allow 
+	// themes to scale the target size, e.g. for mobile screen sizes
+	$factor = theme('image_resize_filter_scale_factor', $attributes['height'], $attributes['width']);
+	$factor = floatval($factor);				// In case get e.g. a string returned
+	// Only need action if there is some response
+	if ($factor>0 && $factor!=1) {
+		$attributes['width'] = (int) round($factor * $attributes['width']);
+		$attributes['height'] = (int) round($factor * $attributes['height']);
+	}
 	
     // Determine if this image requires a resize.
     if (!isset($resize)) {