Exploring AUC Boosting Approach in Multimodal Biometrics Score Level Fusion

We investigate AdaBoost and bipartite version of Rank- Boost abilities to minimize AUC and its application for score level fusion in multimodal biometric systems. To do this, we customize two methods of weak learner training. Empirical results show comparable AUC for AdaBoost and RankBoost.B which previously was addressed theoretically. We demonstrate exhaustive results among state of the art classifiers and techniques. AdaBoost and RankBoost.B achieve significant performance improvement compared to GMM and SUM rule, and the performance comparable to SVM. Besides empirical results, we show that, instead of adding a constant weak learner in order to maximize AUC using AdaBoost, instances could be weighted initially in each class inversely proportional to the number of instances in the corresponding classes.