Using moment invariants and HMM in facial expression recognition

Moment invariants are invariant under shifting, scaling and rotation. They are widely used in pattern recognition because of their discrimination power and robustness. The HMM method is natural and highly reliable way of recognition. In this paper we propose a method for using moment invariants as features and HMM as the recognition method in facial expression recognition. Sequences of four universal expressions, i.e., anger, disgust, happiness and surprise, are recognised. We attain accuracy as high as 93.75%.