Study about the binary differential joint transform correlator used in pattern recognition

New binary joint transform correlator(BJTC) based on differential operation was proposed.It can well resolve the disadvantages about the bottleneck of real-time processing and thresholding selection in BJTC.The unwanted term in joint power spectrum(JPS) varies slowly compared with wanted term.It is reasonable to use differential operation to improve JTC's contrast by depressing the auto-correlate peak and enhancing the cross-correlate peak.Then the differential JPS was binarized to only two values at Fourier plane before inverse Fourier transform.Then higher cross-correlate output between references and object image can be obtained.Simulation results show the proposed JTC can well weakens auto-correlation peak and enhances cross-correlation peak.It also has better robustness.The proposed method can avoid computing or pre-setup threshold.Furthermore,it's quite simple differential operation and binarization require far fewer digital computations than does the BJTC.