def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def block_size_filter(entity):
        return (
            entity.size[0] * 2 >= entity.size[1] * 2
            and entity.size[1] <= 16
            and entity.size[3] <= 4
        )