APPLICATION OF SERIAL-PROJECTION AND PARALLEL-PROJECTION METHODS TO CORRELATION-FILTER DESIGN

We describe generalized projection procedures for the design of arbitr ary filter functions for correlators. More specifically, serial and pa rallel implementations of projection-based algorithms are employed. Th e novelty of this procedure lies in its generality and its ability to handle wide varieties of constraints by the same procedure. The proced ure is demonstrated by the design of filters for the 4-f linear correl ator, the phase-extraction correlator, and variants thereof. The filte rs are subject to a variety of constraints, including rotation-invaria nt pattern recognition and class discrimination. Examples are given to show the versatility, flexibility, and applicability of the design pr ocess to a variety of pattern-recognition tasks. Satisfactory results are also obtained because of the combination with the special nonlinea r correlators proposed for pattern recognition.