https://davey.tistory.com/entry/Python-opencv-%EC%9D%B4%EC%9A%A9%ED%95%98%EC%97%AC-%EC%B9%B4%EB%A9%94%EB%9D%BC-%EC%B6%9C%EB%A0%A5-%ED%95%98%EB%8A%94-%EB%B0%A9%EB%B2%95-%EC%9D%B4%EB%AF%B8%EC%A7%80-%EC%97%B0%EC%86%8D%EC%9C%BC%EB%A1%9C-%EC%B6%9C%EB%A0%A5-%ED%95%98%EB%8A%94-%EB%B0%A9%EB%B2%95
https://076923.github.io/posts/Python-opencv-3/
