Itseez/opencv — pull request #2237 by ivylee (2014-01-30 21:56:36+00:00)
Title: Fixed Bug #3514 Incorrect Chi-Square distance used in LBPH FaceRecognize...

When using LBPH face recognizer, in prediction, the algorithm computes the Chi-Square distance between two spatial histograms, the correct Chi-Square distance should be CV_COMP_CHISQR_ALT introduced in this commit:
https://github.com/vkocheganov/opencv/commit/086db9d6db73956be2ee18b8a552a9179da6b6fd

Reference paper regarding LBPH: Ahonen, T., Hadid, A., and Pietikainen, M. Face Recognition with Local Binary Patterns. Computer Vision - ECCV 2004 (2004), 469–481.