public function watermarkImagePNG($srcim, $logoim, $return=’resource’) {
if (!$srcim) die(__FUNCTION__.’: watermark could not be created 1′);
if (!$logoim) die(__FUNCTION__.’: watermark could not be created 2′);

$src_w = imagesx($srcim);
$src_h = imagesy($srcim);

$logo_w = imagesx($logoim);
$logo_h = imagesy($logoim);

imageAlphaBlending($logoim, false);
imageSaveAlpha($logoim, true);

imagecopy($srcim, $logoim, $src_w/2-$logo_w/2, $src_h/2-$logo_h/2, 0, 0,
$logo_w, $logo_h);

if ($return==’resource’) {
return $srcim;
}
elseif ($return==’output’) {
return imagejpeg($srcim);
}
else {
die(__FUNCTION__.’: unknown output type’);
}
}