opencv facerecognizer tutorial llink

http://hanzratech.in/2015/02/03/face-recognition-using-opencv.html

http://answers.opencv.org/question/82294/cant-get-predict-confidence/

https://courses.cit.cornell.edu/ece5990/ECE5990_Fall15_FinalProjects/Andre_Heil/ece5990_final_report/avh34_jr986.html