Face recognition using Haar's cascades and Local Binary Patterns.
[1] Face Recognition using Python and OpenCV Feb 3, 2015 • Bikramjot Singh Hanzra http://hanzratech.in/2015/02/03/face-recognition-using-opencv.html
[2] Распознаем лица на фото с помощью Python и OpenCV 18 мая 2016 в 11:10 • galvanom https://habr.com/ru/post/301096/
[28.12.2019]:
fixed inputs bugs (OpenCV doesn't work with .gif-files)
found error with recognizer.predict module