Abstract

N-dimensional filters generalize the notion of a filter as a vector in a signal space to a filter acting as a N-dimensional subspace in a signal space.¹,² This new approach to filtering is easily implemented in an optical correlator by time-integrating the response of a series of filters on the output detector array. The resulting response is then threshold detected to determine if a target is present. This improves target discrimination for distortion-invariant recognition and helps alleviate the disparity between the operating speed of the filter spatial light modulator and the output detector array.² An algorithm for designing distortion-invariant N-dimensional filters is presented, and simulation results will be given.

© 1990 Optical Society of America