Three- and four-dimensional filter operations by coherent optics

Three- and four-dimensional signals can be replaced by twodimensional sequences of sectional images if sampling in one or two dimensions is practicable. The convolution of such sequences yields, under certain conditions, the sequence representation of the three- or four-dimensional convolution result. Thus higher-dimensional filter operations can be performed by means of twodimensional filter methods, e.g. coherent optics, whose parallel computing power matches the usually high space-bandwidth products (SBP) of such sequences. The possible throughput of coherent-optical setups is estimated. Experimental results for three-dimensional filter operations are shown.