Как наложить вотермарк в фотогалерее InstantCMS 2?

$preset = array('width' => 900, 'height'=>600, 'is_square'=>false, 'is_watermark'=>true);
 
		if (!empty($this->options['preset'])){
			$preset = cmsCore::getModel('images')->getPresetByName($this->options['preset']);
		}
 
        $result['paths'] = array(
            'big' => $uploader->resizeImage($result['path'], array('width'=>$preset['width'], 'height'=>$preset['height'], 'square'=>$preset['is_square'], 'quality'=>(($preset['is_watermark'] && !empty($preset['wm_image'])) ? 100 : $preset['quality']))),
            'normal' => $uploader->resizeImage($result['path'], array('width'=>300, 'height'=>200, 'square'=>false)),
            'small' => $uploader->resizeImage($result['path'], array('width'=>64, 'height'=>64, 'square'=>false)),
			'original' =>  $uploader->resizeImage($result['path'], array('width'=>1200, 'height'=>800, 'square'=>false, 'is_watermark'=>true)),
        );
 
		if ($preset['is_watermark'] && !empty($preset['wm_image'])){
			img_add_watermark(
					$result['paths']['big'],
					$preset['wm_image']['original'],
					$preset['wm_origin'],
					$preset['wm_margin'],
					$preset['quality']
			);
		}