Buenas!!!
pues yo tengo este codigo que uso y funciona perfectamente
Código PHP:
<?php
// Load the stamp and the photo to apply the watermark to
$foto = "photo.jpg";
echo protegefoto($foto);
function protegefoto($fotop)
{
$proteg = "stamp.png";
$stamp = imagecreatefrompng($proteg);
$im = imagecreatefromjpeg($fotop);
// Set the margins for the stamp and get the height/width of the stamp image
$marge_right = 10;
$marge_bottom = 10;
$sx = imagesx($stamp);
$sy = imagesy($stamp);
// Copy the stamp image onto our photo using the margin offsets and the photo
// width to calculate positioning of the stamp.
imagecopy($im, $stamp, imagesx($im) - $sx - $marge_right, imagesy($im) - $sy - $marge_bottom, 0, 0, imagesx($stamp), imagesy($stamp));
// Output and free memory
header('Content-type: image/png');
imagepng($im);
imagedestroy($im);
}
?>
adaptado a tus necesidades
un saludo!!