premetto che la tua funzione ancora non l'ho provata...


cmq posto questa che ho trovato nel forum (by daniele_dll)

Codice PHP:
function resize_image($img_res$maxX$maxY) {
                
$actualX=imagesx($img_res);
                
$actualY=imagesy($img_res);
                
                if (
$actualX>$maxX) {
                        
$newX=$maxX;
                        
$newY=($actualY/$actualX)*$newX;
                } else {
                        
$newY=$maxY;
                        
$newX=($actualX/$actualY)*$newY;
                }
                
                
$tmp_img_res imagecreatetruecolor($newX$newY);
                
                
$res imagecopyresampled($tmp_img_res$img_res0000$newX$newY$actualX$actualY);
                return 
$tmp_img_res;
        }

        function 
save_image($img_res$filename$quality=80) {
                
imagejpeg($img_res$filename$quality);
        }

        function 
print_image($img_res$quality=80) {
                
header('Content-Type: image/jpeg');
                
imagejpeg($img_res,NULL$quality);
        }
        
       
/* $img_res = imagecreatefromjpeg('./test.jpg');
        $new_img_res = resize_image($img_res, 60, 80);
        unset($img_res);
        print_image($new_img_res, 100);
        unset($new_img_res);*/