In my project I need to detect rotated and non-rotated faces in real time. I read original articles and try to use common implementation in matlab and openCV. And as I understood Haar features are not rotation invariant. What should I do for successes detection of rotated faces ? I have some ideas about it. Which is more 'real'?
- Try to rotate original image with some angle step
- Train own classifier on rotated examples
- Use any modified Viola Jones Algorithm from research articles
- Use another algorithm (like SURF, KLT, Skin based face detection)