1.OpenCV

https://docs.opencv.org/master/db/d3a/facedetect_8cpp-example.html

https://docs.opencv.org/master/db/d7c/group__face.html

https://blog.csdn.net/zuidao3105/article/details/79346591

https://blog.csdn.net/sinat_26917383/article/details/69831495

https://blog.csdn.net/shadow_guo/article/details/44114421

2.Cloud API

百度AI：https://ai.baidu.com/docs#/Face-Detect/top （face qualities／landmark72）

Face++：https://console.faceplusplus.com.cn/documents/4888373（HumanBody／Gesture）

MS：https://docs.microsoft.com/en-us/azure/cognitive-services/face/overview（Face detection／Face landmarks／Head pose／Face attributes）

3.Open Library

https://github.com/ageitgey/face_recognition（http://dlib.net）

https://github.com/seetaface/SeetaFaceEngine

http://www.arcsoft.com.cn/ai/arcface.html

https://github.com/accord-net/framework

http://www.aforgenet.com/framework/

http://www.emgu.com/wiki/index.php/Main_Page

4.Machine Learning

https://pjreddie.com/darknet/yolo/ (YOLO: Real-Time Object Detection)

https://github.com/allanzelener/YAD2K

https://github.com/mbhybird/keras-yolo3

Face Recognition Algorithms