A combined method of expression feature extraction with particle swarm optimization(PSO)and independent component analysis(ICA)is proposed.The basic ICA algorithm is used to derive the independent base vector from the ex-pression images.To decrease the computing complexity,the dimension of the expression image is reduced,and then PSO al-gorithm is applied to process expression data set to get the best optimal solution set.Finally,Hidden Markov Model is used to validate the correctness and validity of the al...