Two-dimensional image correlator

Abstract

The electro-optical correlator performs pattern-recognition by forming the columnar dot product of an input image with a reference image at video through-put rates. The correlator incorporates an analog-to-digital converter for digitizing the input-image data, a plurality of serially arranged delays having a delay time equivalent to one input-image data line, each delay for receiving in turn the digitized input data and for producing a parallel output signal, and a vertical column of photodiodes for receiving the respective multiple parallel delayed signals and for converting same to an optical output. The optical output is fed through a lens, reference image mask, and lens unit and is focused on a plurality of photodiodes that are connected to a time-delay-and-integrate (TDI) array. The data from the time- delay-and-integrate array are clocked through an analog-to- digital converter which produces the final system output. The time delay and integrate array may be a charge-coupled device (CCD).