Joint Discriminative Bayesian Dictionary and Classifier Learning

We propose to jointly learn a Discriminative Bayesian dictionary along a linear classifier using coupled Beta-Bernoulli Processes. Our representation model uses separate base measures for the dictionary and the classifier, but associates them to the class-specific training data using the same Bernoulli distributions. The Bernoulli distributions control the frequency with which the factors (e.g. dictionary atoms) are used in data representations, and they are inferred while accounting for the class labels in our approach. To further encourage discrimination in the dictionary, our model uses separate (sets of) Bernoulli distributions to represent data from different classes. Our approach adaptively learns the association between the dictionary atoms and the class labels while tailoring the classifier to this relation with a joint inference over the dictionary and the classifier. Once a test sample is represented over the dictionary, its representation is accurately labelled by the classifier due to the strong coupling between the dictionary and the classifier. We derive the Gibbs Sampling equations for our joint representation model and test our approach for face, object, scene and action recognition to establish its effectiveness.