Index: wp-includes/media.php
===================================================================
--- wp-includes/media.php	(revision 21940)
+++ wp-includes/media.php	(working copy)
@@ -453,7 +453,14 @@
 	if ( !is_null($dest_path) and $_dest_path = realpath($dest_path) )
 		$dir = $_dest_path;
 	$destfilename = "{$dir}/{$name}-{$suffix}.{$ext}";
-
+	
+	$destfilename = apply_filters('image_resize_set_file_name', array(
+		'proposed_file_path' => $destfilename,
+		'suffix' => $suffix,
+		'extension' => $ext,
+		'original' => $file
+	));
+	
 	if ( IMAGETYPE_GIF == $orig_type ) {
 		if ( !imagegif( $newimage, $destfilename ) )
 			return new WP_Error('resize_path_invalid', __( 'Resize path invalid' ));