Accuracy Analysis in Fingerprint Authentication Using the Fractional Fourier Transform without Misalignment Correction of Scanned Images

摘要

In many fingerprint authentication devices, a frame to insert the fingertip or a hollow to put the fingertip is used to avoid the position or rotation misalignment of a newly scanned genuine fingerprint image, when the fingerprint authentication is conducted. Moreover, the misalignment correction by the numerical calculation is indispensable for the fingerprint authentication devices to achieve the high accuracy. In this study, we investigated the effects of misalignment of the scanned genuine fingerprint image with the one used for generating the template on the accuracy in our fingerprint authentication method using the fractional Fourier transform (FRT). As a result, it was found that our method can achieve high authentication accuracy under the condition that the position-misalignment ratio is 17.6% or less and the rotation misalignment (rotation angle) is 28 degrees or less, even if the misalignment correction is not conducted.