<?php

function watermark($file, $watermark, $pos = null, $x = 0, $y = 0){

$details = getimagesize($file);

$wDetails = getimagesize($watermark);

if(!is_null($pos)){

switch($pos){

case TOP_LEFT:

$x = 0;

$y = 0;

break;

case TOP_RIGHT:

$x = $details[0] - $wDetails[0];

$y = 0;

break;

case BOTTOM_LEFT:

$x = 0;

$y = $details[1] - $wDetails[1];

break;

case BOTTOM_RIGHT:

$x = $details[0] - $wDetails[0];

$y = $details[1] - $wDetails[1];

break;

case CENTER:

$x = round(($details[0] - $wDetails[0])/2);

$y = round(($details[1] - $wDetails[1])/2);

break;

}

}

switch($details['mime']){

case 'image/jpeg':$im = imagecreatefromjpeg($file);break;

case 'image/gif':$im = imagecreatefromgif($file);break;

case 'image/png':$im = imagecreatefrompng($file);break;

}

switch($wDetails['mime']){

case 'image/jpeg':$newWater = imagecreatefromjpeg($watermark);break;

case 'image/gif':$newWater = imagecreatefromgif($watermark);$colorTransparent = imagecolortransparent($newWater);imagefill($newWater, 0, 0, $colorTransparent);imagecolortransparent($newWater, $colorTransparent);break;

case 'image/png':$newWater = imagecreatefrompng($watermark);imagealphablending($newWater, false);imagesavealpha($newWater,true);break;

}

imagecopyresampled($im, $newWater, $x, $y, 0, 0, $wDetails[0], $wDetails[1], $wDetails[0], $wDetails[1]);

// Output the image

switch($details['mime']){

case 'image/jpeg':header('Content-type: image/jpeg');imagejpeg($im);break;

case 'image/gif':header('Content-type: image/gif');imagegif($im);break;

case 'image/png':header('Content-type: image/png');imagepng($im);break;

}

 
// Free up memory

imagedestroy($im);

}

 
// Watermark using only the defaults

watermark('girl.jpg','watermark.png');

 
// Watermark using a pre-defined position

// Valid values: TOP_LEFT, TOP_RIGHT, BOTTOM_LEFT, BOTTOM_RIGHT, CENTER

watermark('girl.jpg','watermark.png', BOTTOM_RIGHT);

 
// Watermark using an exact position

watermark('girl.jpg','watermark.png', null, 150, 150);

 
// Note that you can only use this function once per page.

// If it is used more than one time, the image that will be displayed

// will be the first function called.

?>