抄録
In this paper, we propose the way to modify gradient of fingerprint images. We modify the gradient using fingerprint area and contour, without extracting end points or bifurcation points called “minutia" from fingerprint images. It takes 3.2[ms] to modify fingerprint gradient by using a personal computer which operates at 1000[MHz] clock frequency. Our program code is so light weight that it is able to be embedded in fingerprint verification devices which operate at lower speeds. We evaluated our algorithm by using fingerprint images tilted respectively 0°, 5°, 10° and 15°. Without modifying gradient, we achieved 90.8[%] recognition rate by images tilted from 0° to 5°, while false acceptance rate is 0.01[%]. By using our gradient modification algorithm, recognition rate raised from 90.8[%] to 98.2[%]. On the other hand, 19.4[%] recognition rate was achieved by images tilted from 10° to 15° without gradient modification, and the rate raised to 89.2[%] with gradient modification. The users who don't get used to fingerprint devices tend to input his finger tilted on scanner. Thus, it is expected that the fingerprint verirification device will be improved to be more friendly for all peoples, by using our gradient modification algorithm.
