Multiplexed coherent optical processor for calculating generalized moments

Abstract

A coherent optical processor capable of calculating generalized moments of a two-dimensional pattern is described. A spatial-frequency multiplexing scheme is used to provide for parallel computation of multiple moments. The use of a computer-generated holographic mask permits complete flexibility in choosing moment-generating functions; e.g., the functions could be complex or have a predetermined weighting function. Experimentally, calculation of five geometric moments (corresponding to x, y, xy, x2, and y2) is demonstrated for simple objects. The special features of the proposed coherent optical processor and its space–bandwidth requirements are also discussed.