Features classification using geometrical deformation feature vector of support vector machine and active appearance algorithm for automatic facial expression recognition

Abstract

This paper proposes a method for facial expression recognition in image sequences. Face is detected from the scene and then facial features are detected using image normalization, and thresholding techniques. Using an optimization algorithm the Candide wire frame model is adapted properly on the first frame of face image sequence. In the subsequent frames of image sequence facial features are tracked using active appearance algorithm. Once the model fits on the first frame, animation parameters of model are set to zero, to obtain the shape of model for the neutral facial expression of the same face. The last frame of the image sequence corresponds to greatest facial expression intensity. The geometrical displacement of the Candide wire frame nodes, between the neutral expression frame and the last frame, is used as an input to the multiclass support vector machine, which classifies facial expression into one of the class such as happy, surprise, sadness, anger, disgust, fear and neutral. This method is applicable for frontal as well as tilted faces with angle $$\pm 30\,^{\circ }, \pm 45\,^{\circ }, \pm 60\,^{\circ }$$ ± 30 ? , ± 45 ? , ± 60 ? with respect to y axis.