Joint transform correlator based on off-focus inputting and spherical wave illuminating power spectrum

An improved joint transform correlation technique is proposed for efficient multiple-target detection. The proposed technique employs off-focus inputting and spherical wave illuminating joint power spectrum to overcome false-target detection by eliminating the false correlation peaks while alleviating the effects of noise and other artifacts. Compared with the reported techniques, the proposed method does not need preprocessing for reference image and Fourier plane phase filtering, which makes the recognition process more suitable for all-optical setup to be realized. Thus the speed advantage of the recognition system is more prominent. Moreover, the proposed technique can maximize the utilization efficiency of the space-bandwidth product and the CCD by the new input method. The feasibility and effectiveness of the proposed method are demonstrated by numerical results.