说明：  knn算法 这段时间用opencv中的机器学习算法做了一下目标检测，效果还是不错的。但都是按照命令和库进行调用，基本对我来说是个黑盒子。固然工程师要会用工具，但如果不深入理解内部实现，是很难进步的。所以我打算花上一些时间（可能两个月以上）来学习一下机器学习的基本概念，并且用python语言去实现一些经典的算法，希望自己能坚持下去吧～
(his period of time using OpenCV machine learning algorithm to do a target detection, the effect is still good. But they are called according to the command and library, which is basically a black box for me. Although engineers need to be able to use tools, it is difficult to make progress without a deep understanding of the internal implementation. So I plan to spend some time (maybe more than two months) to learn the basic concepts of machine learning, and use Python to implement some classic algorithms. I hope I can stick to it)