https://github.com/MauryaRitesh/Facial-Expression-Detection
https://github.com/valterlucena/facial-expression-detector
deepface:
https://github.com/serengil/deepface
cnn based facial expression recognizer:
https://github.com/WuJie1010/Facial-Expression-Recognition.Pytorch/issues
predict human emotion:
https://github.com/thoughtworksarts/EmoPy
facial expression recognization:
https://github.com/phamquiluan/ResidualMaskingNetwork
smile detection using opencv:
https://www.geeksforgeeks.org/python-smile-detection-using-opencv/