si la uso.. la uso nel resize ecco a te .. la metto senza i code del forum e se c'è qualche mod la può mettere dentro i code del forum che a me non riesco:

if(isset($_POST['submit_upload'])){

$file = explode('.',$_FILES['upload_file']['name']);
$file_name = sha1($_FILES['upload_file']['name']).'.'.$file[count($file)-1];
move_uploaded_file($_FILES['upload_file']['tmp_name'], "".$dir_admin_photo."".$row_dir."/tmp/".$_FILES['upload_file']['name']."");
$resizer = new ImageResizer("".$dir_admin_photo."".$row_dir."/tmp/".$_FILES['upload_file']['name']."","".$dir_admin_photo."".$row_dir."/big/".strtolower($file_name)."");
$resizer->resizeImage(800,600);
$resizer = new ImageResizer("".$dir_admin_photo."".$row_dir."/tmp/".$_FILES['upload_file']['name']."","".$dir_admin_photo."".$row_dir."/thumb/".strtolower($file_name)."");
$resizer->resizeImage(150,150);
unlink("".$dir_admin_photo."".$row_dir."/tmp/".$_FILES['upload_file']['name']."");

$msg = "Fatto";
?>
<a href="javascript:save_photo('<?php echo $file_name; ?>')"><?php echo $file_name; ?></a>
<?php


}