Face recognition and subject verification. In a first approach, we show that the external features encoded in the NMF coefficients yield enough useful information for classification purposes. Then we compare the information contributed by the external features and the internal features. Finally, the last step is to combine the information provided by the external and the internal features. We show that both kinds of information are complementary, providing and extra information cue that can improve the classification results in presence of occlusions and local changes in the illumination.