Immagini incomplete?

[boots]

error_reporting(E_ALL);
set_error_handler("noticeHandler", E_NOTICE);
function noticeHandler($errno, $errstr){
   throw new Exception($errstr);
}

try{
  ...
  $im = imagecreatefromjpeg(...);
  ...
}catch(Exception $ex){
 echo $ex->getMessage();
}