Automatic Expression Recognition Based on Mouth Shape Analysis

This paper presents a simple approach for facial expression recognition. In the preprocessing stage, rough lips region is obtained from original face image using HSI space. Then, based on the binary image, exact lips region is located within a rectangle. To achieve this goal, PSO algorithm is applied to search for the best rectangle region. Finally, expression is estimated based on the parts ratio of lips. The simulation results show that this geometric approach is accurate and effective, even for the slightly smile.