Techniques to improve binary joint transform correlator, particularly for fingerprint recognition

摘要

In a binary joint transform correlator, a Fourier plane binarization threshold is provided which alternates between even and odd rows and reduces noise in the output plane and improves discrimination between matched and unmatched prints. Periodically correlating with a known standard input and normalizing the output peak intensity prevents correlator performance drift from degrading fingerprint recognition performance. Experimental system performance is assessed statistically, in terms of the false pass rate seen when operating with a constant false alarm rate. By applying both techniques, a false pass improvement from 6.95% to 0.076% is experimentally demonstrated at a false alarm rate of 0.1 percent.