OPTIMAL INCOHERENT FILTERING FOR DISTORTION-INVARIANT IMAGE RECOGNITION

An optimal incoherent filter is proposed for distortion-invariant corr elation. The optical transfer function (OTF) of the correlator is spec ified as a realizable phase-only term which is optimized by the simula ted annealing algorithm. The phase-only OTF is used in image recogniti on to produce a sharp peak response and can be generated by dual-filte r synthesis. Image recognition is achieved by subtracting two spatiall y incoherent correlation outputs produced from a positive and negative filters with an input image. Computer simulations show that the propo sed correlator can yield a sharp correlation peak with excellent disto rtion tolerance.