[PHP] Immagini thumbnail brutte...

[Aquila2000]

Salve a tutti, ho scaricato dagli script di php un programmino per creare al volo delle png da jpeg (tnp.php). Funziona bene, ma l'aspetto delle thumbnail è orribile, perde qualsiasi colore, non mantenedo i colori originali delle jpeg.

Qualcuno sa darmi una mano su dove intervenire?

GRAZIE.

<?
if (!isset($image)){ // if not generate an error image
    $img = ImageCreate(100, 100);
    $red = ImageColorAllocate($img, 255, 0, 0);
    $yellow = ImageColorAllocate($img, 255, 255, 0);
    ImageString($img, 5, 20, 20, "No image", $yellow);
    ImageString($img, 5, 20, 40, "name", $yellow);
    ImageString($img, 5, 20, 60, "given!", $yellow);
    ImagePNG($img);
    ImageDestroy($img);
    exit();
}
// check if the 'tnsize' parameter has been given
if (!isset($tnsize)) { // if not generate an error image
    $img = ImageCreate(100, 100);
    $red = ImageColorAllocate($img, 255, 0, 0);
    $yellow = ImageColorAllocate($img, 255, 255, 0);
    ImageString($img, 5, 20, 20, "No thumb", $yellow);
    ImageString($img, 5, 20, 40, "size", $yellow);
    ImageString($img, 5, 20, 60, "given!", $yellow);
    ImagePNG($img);
    ImageDestroy($img);
    exit();
}
// ensure that $tnsize is an integer 
$tnsize = (integer) $tnsize;
// check that the size asked for is sensible
if (($tnsize<20) or ($tnsize>300)){ // if not generate an error image
    $img = ImageCreate(100, 100);
    $red = ImageColorAllocate($img, 255, 0, 0);
    $yellow = ImageColorAllocate($img, 255, 255, 0);
    ImageString($img, 5, 20, 20, "Bad", $yellow);
    ImageString($img, 5, 20, 40, "size", $yellow);
    ImageString($img, 5, 20, 60, "given!", $yellow);
    ImagePNG($img);
    ImageDestroy($img);
    exit();
}
// attempt to load the big image
if (!$bigimage = @ImageCreateFromJPEG($image)) {    // if loading fails
    $img = ImageCreate(100, 100);                    // generate an error
    $red = ImageColorAllocate($img, 255, 0, 0);        // image
    $yellow = ImageColorAllocate($img, 255, 255, 0);
    ImageString($img, 5, 20, 20, "Image", $yellow);
    ImageString($img, 5, 20, 40, "not", $yellow);
    ImageString($img, 5, 20, 60, "found!", $yellow);
    ImagePNG($img);
    ImageDestroy($img);
    exit();
}
$tnimage = ImageCreate($tnsize, $tnsize);
$darkblue = ImageColorAllocate($tnimage, 0, 0, 127);
ImageColorTransparent($tnimage,$darkblue);
$sz = GetImageSize($image);
$x = $sz[0];    // big image width
$y = $sz[1];    // big image height
if ($x>$y) {    // if it is the width then
    $dx = 0;                    // the left side of the new image
    $w = $tnsize;                // the width of the new image
    $h = ($y / $x) * $tnsize;    // the height of the new image
    $dy = ($tnsize - $h) / 2;    // the top of the new image
}else{    // if the height is larger then
    $dy = 0;                    // the top of the new image
    $h = $tnsize;                // the height of the new image
    $w = ($x / $y) * $tnsize;    // the width of the new image
    $dx = ($tnsize - $w) / 2;    // the left edgeof the new image
}
ImageCopyResized($tnimage, $bigimage, $dx, $dy, 0, 0, $w, $h, $x, $y);
ImagePNG($tnimage);
ImageDestroy($tnimage);
ImageDestroy($bigimage);
// all done!
?>