活体检测

https://zhuanlan.zhihu.com/p/50139673

https://zhuanlan.zhihu.com/p/60627380

https://zhuanlan.zhihu.com/p/69733383

https://www.zhihu.com/topic/20095248/hot

https://www.jianshu.com/p/16d30bd6344e