protect images from being copied

$reqinfo['id'] = $data[id];
$reqinfo['maxsize'] = 320;
$reqinfo['timestamp'] = time();
$reqinfo['base'] = false;

$encoded = base64_encode(openssl_encrypt(serialize($reqinfo), 'AES-128-CBC', 'martine',0,'fgrgfvcfghtfdrfg'));

echo'<div class="imagecontainer"><img src="photo.php?info='.$encoded.'" /></div>'; 

<?
//request info
$reqinfo = unserialize(openssl_decrypt(base64_decode($_GET[info]), 'AES-128-CBC', 'martine',0,'fgrgfvcfghtfdrfg'));

//image expired
if(time() - $reqinfo[timestamp] > 10){ exit(); }

//public image
if($reqinfo[base] == true){ readfile('img/'.$reqinfo[id].'.jpg'); exit(); }

//header cache
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past
header('Content-type: image/jpeg');

//check cache existance and send out
if(file_exists( 'img/'.$reqinfo[id].'_'.$reqinfo[maxsize].'.jpg')) { readfile('img/'.$reqinfo[id].'_'.$reqinfo[maxsize].'.jpg'); exit(); }

//source Image
$image_path = 'img/'.$reqinfo[id].'.jpg';
list($original_width, $original_height)= getimagesize($image_path); 
$srcImage = imagecreatefromjpeg( $image_path );
$ratio = $original_height/$original_width;


//create destination image holder
$destination_width = $reqinfo['maxsize'];
if($destination_width < 1) $destination_width = 1;
if($destination_width > $original_width)$destination_width = $original_width;
$destination_height = round($destination_width*$ratio);
if ($destination_height > $reqinfo['maxsize'])
{
    $destination_height = $reqinfo['maxsize'];
    $destination_width = round($destination_height/$ratio);
}
$targetImage = imagecreatetruecolor( $destination_width, $destination_height );
imagealphablending($targetImage,true);

//resample copy logo
imagecopyresampled( $targetImage, $srcImage, 
0, 0, 
0, 0, 
$destination_width, $destination_height, 
$original_width, $original_height );


// watermark
$watermark = imagecreatefrompng('watermark.png');
imagesettile($targetImage, $watermark);
imagefilledrectangle($targetImage, 0, 0, $destination_width, $destination_height, IMG_COLOR_TILED);




//output
imagejpeg(  $targetImage, 'img/'.$reqinfo[id].'_'.$reqinfo[maxsize].'.jpg' );
imagejpeg(  $targetImage );
imagedestroy( $targetImage );


?>