public function regenerate() {
		$operations = Configure::read('FileStorage.imageSizes.' . $this->args[0]);
		$options = [
			'overwrite' => !$this->params['keep-old-versions']
		];

		if (empty($operations)) {
			$this->abort(__d('file_storage', 'Invalid table or version.'));
		}

		foreach ($operations as $version => $operation) {
			try {
				$this->_loop($this->command, $this->args[0], [$version => $operation], $options);
			} catch (Exception $e) {
				$this->abort($e->getMessage());
			}
		}
	}