PIC-Score: Probabilistic Interpretable Comparison Score for Optimal Matching Confidence in Single- and Multi-Biometric (Face) Recognition

TL;DR

This paper introduces PIC-Score, a probabilistic and interpretable method for assessing matching confidence in biometric systems, especially face recognition, improving accuracy and interpretability over existing methods.

Contribution

The paper presents a novel PIC-Score that provides optimal probabilistic confidence estimates and effectively combines multiple samples for enhanced biometric recognition.

Findings

PIC-Score outperforms existing confidence estimation methods.

It provides more accurate probabilistic interpretation.

Effective in multi-biometric face recognition scenarios.

Abstract

In the context of biometrics, matching confidence refers to the confidence that a given matching decision is correct. Since many biometric systems operate in critical decision-making processes, such as in forensics investigations, accurately and reliably stating the matching confidence becomes of high importance. Previous works on biometric confidence estimation can well differentiate between high and low confidence, but lack interpretability. Therefore, they do not provide accurate probabilistic estimates of the correctness of a decision. In this work, we propose a probabilistic interpretable comparison (PIC) score that accurately reflects the probability that the score originates from samples of the same identity. We prove that the proposed approach provides optimal matching confidence. Contrary to other approaches, it can also optimally combine multiple samples in a joint PIC score which further increases the recognition and confidence estimation performance. In the experiments, the proposed PIC approach is compared against all biometric confidence estimation methods available on four publicly available databases and five state-of-the-art face recognition systems. The results demonstrate that PIC has a significantly more accurate probabilistic interpretation than similar approaches and is highly effective for multi-biometric recognition. The code is publicly-available.