private function output($save_path)
	{
		if ($this->resource != null)
		{
			switch ($this->image_type)
			{
				case IMAGETYPE_PNG:
					imagepng($this->resource, $save_path);
					break;

				case IMAGETYPE_GIF:
					imagegif($this->resource, $save_path);
					break;

				case IMAGETYPE_JPEG:
					imagejpeg($this->resource, $save_path);
					break;
			}
		}
	}