Score reliability based weighting technique for score-level fusion in multi-biometric systems

The performance of multiple matchers heavily influence the recognition accuracy of a multi-biometric system under the simple sum-rule-based score-level fusion. In this paper, a weighting technique, referred to as score reliability based weighting (SRBW) technique, is developed to estimate weights for the matchers in order to improve the recognition rate of multi-biometric systems at the score level. In the proposed technique, the reliabilities are computed directly from the raw matching scores obtained from the individual matchers. The proposed weighting technique does not require a priori knowledge of the rankings of matching scores, or the equal error rates, or the genuine/impostor score distributions of the individual matchers used in the system. The experimental results show that the performance of a multi-biometric system using the proposed weighting technique is superior to that of the uni-biometric systems or to that of the multi-biometric systems using the existing weighting techniques in terms of equal error rate and genuine acceptance rate at 1% false acceptance rate.