How to align face images c++ opencv

Question

I am developing a C++ application for face authentication. First, I have to detect the face and pre-process the image.

1. For face detection I have used the HaarC

Answer 1

I tried the following face alignment code from the Labelled Faces in the Wild project page. It works really well and does not require detecting facial feature points. The C++ code can be downloaded from: http://vis-www.cs.umass.edu/faceAlignment/

If you still wish to find face key points, I find that the Viola-Jones detector is not very robust and accurate. I personally recommend using the Flandmark face keypoint detector: http://cmp.felk.cvut.cz/~uricamic/flandmark/ which is much much more robust and accurate. C code can be downloaded from the above site.