Jacobian and Hessian: http://jacoxu.com/jacobian%E7%9F%A9%E9%98%B5%E5%92%8Chessian%E7%9F%A9%E9%98%B5/
From traditional detection methods to deep neural network frameworks: http://www.sohu.com/a/131923395_465975
Three powerful object recognition algorithms: https://blog.csdn.net/liuqz2009/article/details/47623647