private function get_optimal_crop( $new_width , $new_height )
	{
		$height_ratio	= $this->height / $new_height;
		$width_ratio	= $this->width /  $new_width;

		if ( $height_ratio < $width_ratio ) {
			$optimal_ratio = $height_ratio;
		} else {
			$optimal_ratio = $width_ratio;
		}

		$optimal_height	= $this->height / $optimal_ratio;
		$optimal_width	= $this->width  / $optimal_ratio;

		return array(
			'optimal_width'		=> $optimal_width,
			'optimal_height'	=> $optimal_height
		);
	}