Is it possible?

[forumnz]

To have a water mark imprinted in an image when it is uploaded? A unique one?

[MadTechie]

Yes

 

read up on GD library

 

IE

 

you need watermark.png (notice use of the PNG format; GD 2.0+ has removed compatibility with GIF images)

 

test.php?src=test.jpg

<?php  

header('content-type: image/jpeg');  

$watermark = imagecreatefrompng('watermark.png');  
$watermark_width = imagesx($watermark);  
$watermark_height = imagesy($watermark);  
$image = imagecreatetruecolor($watermark_width, $watermark_height);  
$image = imagecreatefromjpeg($_GET['src']);  
$size = getimagesize($_GET['src']);  
$dest_x = $size[0] - $watermark_width - 5;  
$dest_y = $size[1] - $watermark_height - 5;  
imagecopymerge($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_width, $watermark_height, 100);  
imagejpeg($image);  
imagedestroy($image);  
imagedestroy($watermark);  

?>

[forumnz]

What bout if a user uploads multiple images and wants a unique number on it?