A Study of Touchless Fingerprint Recognition System

Fingerprint recognition systems are widely used in the field of biometrics. Many existing fingerprint sensors acquire fingerprint images as the user’s fingerprint is contacted on a solid flat sensor. Because of this contact, input images from the same finger can be quite different and there are latent fingerprint issues that can lead to forgery and hygienic problems. For these reasons, a touchless fingerprint recognition system has been investigated, in which a fingerprint image can be captured without contact. While this system can solve the problems which arise through contact of the user’s finger, other challenges emerge, for example, low ridge-valley contrast, and 3D to 2D image mapping. In this paper we discuss both the disadvantages and the advantages of touchless fingerprint systems and introduce the hardware and algorithm approach to solve the problems. We describe the structure of illuminator and the wavelength of light to acquire a high contrast fingerprint images. To solve the problem of 3D to 2D image mapping, we describe the method to remove the strong view difference fingerprint images. Experiments show that the touchless fingerprint system has better performance than the conventional touch based system.