Optical pattern recognition with nonlinear joint transform correlation

Abstract

We review the nonlinear joint transform correlator (JTC) including the kth law nonlinear JTC, and the binary nonlinear JTC. Multiple objects detection using binary joint transform correlation are presented. An optimum threshold function is computed to maximize the light intensity of the correlation peak and to eliminate the even order harmonic terms. The correlation performance of the binary JTC is determined for different thresholding methods. The binary JTC produces large peak to sidelobe ratio and narrow peak for the multiple targets. The optimum threshold function produces better correlation performance compared with the median thresholding.