According to the properties of operator SUSAN, it can be used not only to detect the edge, but also to extract the corner point. Therefore, comparing with the operator such as Sobel, Canny, and so on, it is more appropriate to extract the features of eyes and
mouth on the face, especially to locate the corner points of eyes and mouth automatically. It also can get good achievements on images with various qualities by adjusting the parameters r , and of operator SUSAN.