Performance comparison of illumination methods for finger-vein imaging and liveness detection

Four laser illumination methods based on a diffuser, concave lens, quasi-static microelectromechanical system (MEMS) scanner, and resonant MEMS scanner, were evaluated for finger vein and liveness detections. Repeatability tests were performed on two persons for a quantitative evaluation based on the curvature of the intensity curve. Images of a finger vein and blood flow are compared between the four methods in terms of image contrast. Finger-vein images were quantitatively evaluated, confirming that the performance of the resonant scanner was superior to those of the other methods. The liveness detectability was also validated by extracting the blood flow pattern based on a laser speckle image, showing that the resonant scanner exhibited the best contrasts in both finger-vein and blood flow images, higher by 22.7 and 49.9%, respectively, than those of the other three methods. This indicates that the proposed method with the resonant scanner enhances the capability for identity authentication with anti-spoofing.