Illumination scheme for high-contrast, contactless fingerprint images
Lirong Wang, Rania H. Abd El-Maksoud, José Sasián, Valorie S. Valencia · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2009
Illumination is critical to achieve high-contrast, contactless fingerprint images. In this paper, we report results of fingerprint imaging experiments performed under different illumination conditions. We studied how polarization states, illumination wavelength, detection wavelength, and illumination direction influence the contrast of fingerprint images. Our research findings provide a selection rule for optimum illumination and a basis for us to construct an illuminator that generates uniform illumination and high-contrast contactless fingerprint images.