Index: modules/image/image.install
===================================================================
--- modules/image/image.install	(revision 3)
+++ modules/image/image.install	(working copy)
@@ -122,13 +122,13 @@
       'alt' => array(
         'description' => "Alternative image text, for the image's 'alt' attribute.",
         'type' => 'varchar',
-        'length' => 128,
+        'length' => variable_get('image_title_length', 500),
         'not null' => FALSE,
       ),
       'title' => array(
         'description' => "Image title text, for the image's 'title' attribute.",
         'type' => 'varchar',
-        'length' => 128,
+        'length' => variable_get('image_title_length', 500),
         'not null' => FALSE,
       ),
     ),