Efficient rectangle feature extraction for real-time facial expression recognition based on AdaBoost

In this paper, we propose a method of selecting new types of rectangle features that are suitable for facial expression recognition. The basic concept in this paper is similar to Violar's approach, which is used for face detection. Instead of previous Haar-like rectangle features we choose rectangle features for facial expression recognition among all possible rectangle types in a 3x3 matrix form using the AdaBoost algorithm. Also, the facial expression recognition system constituted with the proposed rectangle features is compared to that with previous rectangle features with regard to its capacity. The results show that the proposed approach has better performance in facial expression recognition in terms of simulation and experimental results.