An Evaluation of Score Level Fusion Approaches for Fingerprint and Finger-vein Biometrics

TL;DR

This paper evaluates various score normalization and fusion techniques for combining fingerprint and finger-vein biometrics, demonstrating that hyperbolic tangent normalization with simple sum fusion yields near-perfect accuracy improvements.

Contribution

It systematically compares score level fusion approaches for multimodal biometrics, identifying the most effective combination for fingerprint and finger-vein modalities.

Findings

Hyperbolic tangent normalization with simple sum fusion achieves 99.98% improvement.

Score fusion significantly enhances biometric system performance over unimodal systems.

The study provides a benchmark for effective score level fusion techniques.

Abstract

Biometric systems have to address many requirements, such as large population coverage, demographic diversity, varied deployment environment, as well as practical aspects like performance and spoofing attacks. Traditional unimodal biometric systems do not fully meet the aforementioned requirements making them vulnerable and susceptible to different types of attacks. In response to that, modern biometric systems combine multiple biometric modalities at different fusion levels. The fused score is decisive to classify an unknown user as a genuine or impostor. In this paper, we evaluate combinations of score normalization and fusion techniques using two modalities (fingerprint and finger-vein) with the goal of identifying which one achieves better improvement rate over traditional unimodal biometric systems. The individual scores obtained from finger-veins and fingerprints are combined at score level using three score normalization techniques (min-max, z-score, hyperbolic tangent) and four score fusion approaches (minimum score, maximum score, simple sum, user weighting). The experimental results proved that the combination of hyperbolic tangent score normalization technique with the simple sum fusion approach achieve the best improvement rate of 99.98%.