public function reset() {
		if (!$this->_image_resource_backup) {
			throw new ImageException('Cannot restore, no backup has been taken for image resource');
		}

		$cloned = $this->cloneResource($this->_image_resource_backup);

		$this->_image_resource = $cloned['resource'];
		$this->updateImageInfo($cloned['width'], $cloned['height']);
		return $this;
	}