public function flip(array $options = []) {
		if (!isset($options['direction'])) {
			$options['direction'] = 'vertically';
		}
		if (!in_array($options['direction'], ['vertically', 'horizontally'])) {
			throw new \InvalidArgumentException(__d('imagine', 'Invalid direction, use vertically or horizontally'));
		}
		$method = 'flip' . $options['direction'];
		$this->_image->{$method}();
		return $this;
	}