Ho usato il tuo script ma mi da un po' di errori:::

Warning: imagesy(): supplied argument is not a valid Image resource in /mounted-storage/home39b/sub007/sc30721-XDAX/www/test_resize_3.php on line 23

Warning: imagesx(): supplied argument is not a valid Image resource in /mounted-storage/home39b/sub007/sc30721-XDAX/www/test_resize_3.php on line 23

Warning: Division by zero in /mounted-storage/home39b/sub007/sc30721-XDAX/www/test_resize_3.php on line 23

Fatal error: Call to undefined function is_set_config() in /mounted-storage/home39b/sub007/sc30721-XDAX/www/test_resize_3.php on line 24