Curvewise DET Confidence Regions and Pointwise EER Confidence Intervals Using Radial Sweep Methodology

Abstract

One methodology for evaluating the matching performance of biometric authentication systems is the detection error tradeoff (DET) curve. The DET curve graphically illustrates the relationship between false rejects and false accepts when varying a threshold across a genuine and an imposter match score distributions. This paper makes two contributions to the literature on the matching performance evaluation of biometric identification or bioauthentication systems. First, we create curvewise DET confidence regions using radial sweep methods. Second we use this same methodology to create pointwise confidence intervals for the equal error rate (EER). The EER is the rate at which the false accept rate and the false reject rate are identical. We utilize resampling or bootstrap methods to estimate the variability in both the DET and the EER. Our radial sweep is based on converting the false reject and false accept errors to polar coordinates. Application is made of these methods to data from three different biometric modalities and we discuss the results of these applications.