NONLINEAR JOINT TRANSFORM CORRELATOR BY INTERFRAME PROCESSING OF MULTI-INTENSITY IMAGERY

In a nonlinear joint transform correlator, the joint power spectrum (J PS) is detected by a CCD camera before nonlinear processing. Since the JPS is a high-dynamic-range image, it cannot be recorded by a CCD cam era of narrow response range. The multi-intensity imagery technique is proposed to cope with the detection of the JPS by a CCD camera by mul tiple recordings at different intensities. With the multi-intensity im agery an effective nonlinearity by interframe processing of data block ''cut and paste'' can be performed easily to build a high-contrast JP S. The technique can improve the correlation performance significantly by transferring a part of de energy to harmonic terms of interest. Th e involved theoretical explanation and experimental demonstration are given. (C) 1996 Society of Photo-Optical Instrumentation Engineers.