generare miniatura e depositarla

[powerflash]

avrei un quesito da sottoporvi.

in questo esempio viene generata una miniatura da un immagine:

Header("Content-type: image/jpeg");
$larghezza = $_GET["larghezza"];
$altezza = $_GET["altezza"];

$image = "http://www.sito.com/public/".$_GET["file"];
$size = GetImageSize($image);
$height=$size[1]/($size[0]/$larghezza);
/*$thumb = ImageCreate($larghezza,$height);
$image = ImageCreateFromJPEG($image);
ImageCopyResized($thumb,$image,0,0,0,0,$larghezza,$height,$size[0],$size[1]);

ImageJPEG($thumb,'',80);
ImageDestroy($thumb);*/

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_res, 0, 0, 0, 0, $newX, $newY, $actualX, $actualY);
 return $tmp_img_res;
}

function print_image($img_res, $quality=80) {
 header('Content-Type: image/jpeg');
 imagejpeg($img_res,NULL, $quality);
}

$img_res = imagecreatefromjpeg($image);
$new_img_res = resize_image($img_res, $larghezza, $height);
unset($img_res);
print_image($new_img_res, 100);
unset($new_img_res); 

io adesso vorrei depositare il file generato in una cartella, tipo /public (777).