--- a/picture.module	2013-03-06 23:21:03.000000000 +0000
+++ b/picture.module	2013-03-06 23:20:28.000000000 +0000
@@ -1143,6 +1143,10 @@ function picture_image_uri($src) {
     // relative.
     $needles[$scheme] = trim($stream_wrapper->getDirectoryPath(), '/');
 
+    // Convert absolute path to relative path
+    $key = explode($needles[$scheme], $src);
+    $src = str_replace($key[0], '', $src);
+    
     // Check whether the file stream directory is at the beginning of
     // the image src. Use === since strpos could return false.
     if (strpos($src, $needles[$scheme]) === 0) {