POSITION-INVARIANT 2-DIMENSIONAL IMAGE CORRELATION USING A ONE-DIMENSIONAL SPACE INTEGRATING OPTICAL PROCESSOR - APPLICATION TO SECURITY VERIFICATION

We describe a 1-D space integrating optical processor that can perform position-invariant 2-D image correlation by 1-D scanning the input im age over a 2-D reference image along a coordinate axis, which we shall refer to as the x axis in a Cartesian coordination system. The 2-D re ference function is a position-invariant filter that is designed using distortion-invariant pattern recognition techniques to provide tolera nce to misalignments along the y axis between the input image and the reference function during the 1-D spatial correlation. Applications of this system to phase-encoded image recognition and fingerprint recogn ition are described. (C) 1996 Society of Photo-Optical Instrumentation Engineers.