Abstract

The intensity compensation filtering (ICF) peak-sharpening process for a hybrid joint transform correlator (JTC) can be divided into three steps. First, the power spectrum of the reference is taken in by a CCD camera and stored in the computer. The filter function is then obtained from the thresholded inverse of the power spectrum. Second, the object is turned on and the joint Fourier power spectrum is again picked up by the CCD camera and sent to the computer. In the last step, or the readout, the computer displays the filter function and the joint power spectrum on two overlapping SLMs that are illuminated by a coherent readout beam. The correlation peak is detected at the output plane. In some situations, the two SLMs can be combined into one and the multiplication of filter function and joint spectrum is performed by computer, especially if the filter is binarized or ternarized, or when the computer multiplication is swift enough to meet the real-time requirements.

© 1991 Optical Society of America