Finger vein authentication is a personal identification technology using finger vein images acquired by infrared imaging.
It is one of the newest technologies in biometrics. Its main advantage over other biometrics is the low risk of forgery or
theft, due to the fact that finger veins are not normally visible to others. Extracting finger vein patterns from infrared
images is the most difficult part in finger vein authentication. Uneven illumination, varying tissues and bones, and
changes in the physical conditions and the blood flow make the thickness and brightness of the same vein different in
each acquisition. Accordingly, extracting finger veins at their accurate positions regardless of their thickness and
brightness is necessary for accurate personal identification. For this purpose, we propose a new finger vein extraction
method which is composed of gradient normalization, principal curvature calculation, and binarization. As local
brightness variation has little effect on the curvature and as gradient normalization makes the curvature fairly uniform at
vein pixels, our method effectively extracts finger vein patterns regardless of the vein thickness or brightness. In our
experiment, the proposed method showed notable improvement as compared with the existing methods.