Динамический watermark

function img_watermark(&$img, $w, $h){
 
    $inConf = cmsConfig::getInstance();
    $inUser = cmsUser::getInstance();
    if (!$inConf->wmark) { return; }
 
	$wm_file = 	PATH.'/images/'.$inConf->wmark;
 
    if (!file_exists($wm_file)) { return; }
 
    $size = getimagesize($wm_file);
 
	$wm = imagecreatefrompng($wm_file);
 
	$wm_w = $size[0];
	$wm_h = $size[1];
 
	$wm_x = $w - $wm_w;
	$wm_y = $h - $wm_h;
        /* add login and date to picture */
        $black = imagecolorallocate($img, 0x00, 0x00, 0x00); // color
        $font_file = PATH.'/arial.ttf'; // font
        $text = $inUser->login." ".date("d/m/Y"); // some text
        imagefttext($img, 18, 0, $wm_x, $wm_y, $black, $font_file, $text);
        /* add login and date to picture */
	imagecopyresampled($img, $wm, $wm_x, $wm_y, 0, 0, $wm_w, $wm_h, $wm_w, $wm_h);
 
}