Optimal trade-off filter for the correlation of fingerprints
Colin Soutar · Optical Engineering · 1999
We present the derivation of an optimal trade-off filter devel- oped for the correlation of fingerprints. The filter is comprised of multiple versions of the system user's fingerprint (i.e., it is a composite filter). Also, the characteristics of the filter can be adjusted so that its perfor- mance in a correlator is similar to that of a matched filter, an inverse filter, or some compromise between the two. These attributes make this filter structure attractive for the task of fingerprint verification. The com- posite nature of the filter offers distortion tolerance by encompassing several different versions of the fingerprint image, while the tailored char- acteristics of the filter enables us to produce a filter that is a trade-off between this distortion tolerance and its discrimination capability. The filter was developed using a ''standard'' database, with the objective of separating the two classes of input to the system: ''legitimate users'' and ''attackers.'' Specifically, the filter is optimized to minimize the probability of error (i.e., misclassification of user). Both the design and the imple- mentation of the optimal fingerprint filter are covered. © 1999 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(99)00501-2)