A new gait feature called as optimalaxis projection(OAP) is proposed as gait information in this paper.First,the background subtraction is used to extract silhouettes from the regional image sequences.Then we randomly select some silhouette sequences to train the optimal axis based on the principal component analysis(PCA) method,and extract the OAP features through the optimal axis.Experiments on UCSD and SOTON database show that the OAP features contain abundance of gait information.Compared with the same ...