Space integrating joint transform correlator using a moving grating

A new one-step joint transform correlator (JTC) is presented, in which the joint transform of the images to be correlated is filtered by a moving Ronc hi ruling. An alternative JTC architecture without moving parts using two R onchi rulings is also suggested. A lens produces the spatial integral of th e product of the joint transform image and the transmission factor of the R onchi ruling, and a single element detector is used to capture the integral . The amplitude of the light modulation on the detector gives the cross-cor relation function of the input images at coordinates (0,0) without major pr ocessing. Therefore, in principle this technique significantly reduces the time required to evaluate the crosscorrelation function, compared to that f or usual JTCs. Experimental validation of the proposed one-step architectur e is presented. (C) 1999 Society of Photo-Optical Instrumentation Engineers . [S0091-3286(99)01807-3].