HYBRID OPTICAL DIGITAL ACCESS-CONTROL USING FINGERPRINT IDENTIFICATION

Two hybrid optical/digital systems for access control applications in real-time fingerprint identification are presented. Both involve finge rprint acquisition with a prism, optical Fourier transformation by a l ens, data reduction using a wedge-ring detector (WRD), and decision ma king with a digital computer, One, called the coherent system, perform s the fourier transformation on a coherent fingerprint image introduce d directly from a prism, and the other, called the incoherent system, acquires an incoherent fingerprint image, performs preprocessing in a digital computer, and incoherent-to-coherent image conversion before c oherent processing. Both systems use the total internal reflection obt ained in a prism to introduce the fingerprint image. Decision making i s performed by a computer on the WRD output, a feature vector of 64 co mponent digital values. In our experiment, discrimination and error-to lerance performance associated with our two access control systems wer e tested with four different fingerprints, Initial experimental result s show that the incoherent system achieves better performance at the e xpense of additional equipment.