In this paper we investigate alternative designs of a Radial Basis Function Network acting as classifier in a face recognition system. Input to the RBF network is the projections of a face image over the principal components. A database of 250 facial images of 25 persons is used for training and evaluation. Two RBF designs are studied: the forward selection and the gaussian mixture model. Both designs are also compared to the conventional Euclidean and Mahalanobis classifiers. A set of experiments evaluates the recognition rate of each method as a function of the number of principal components used to characterize the image samples. The results of the experiments indicate that the gaussian mixture model RBF achieves the best performance while allowing less neurons in the hidden layer. The gaussian mixture model approach shows also to be less sensitive to the choice of the training set.
Carlos E. Thomaz, Raul Queiroz Feitosa, Alvaro Vei