Projection-generated Fourier descriptors that are robust with respect to both random point noise and occlusion
Edward R. Dougherty, Robert P. Loce · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1990
By generating Fourier descriptors based upon the waveform induced by a pattern''s projection a number ofclassic difficulties with the Fourier-descriptor methodology are mitigated. Not only are the descriptors invariant with respect to scale translation and rotation (as is usually the case) they are also continuous in the Hausdorff metric and robust with respect to both point noise and occlusion insensitivity with respect to minimum occlusions being perhaps their most significant advantage. Continuity in the Hausdorif metric allows prediction of the effect on the descriptors when morphologically filtering a pattern. The effect of occlusion is also predictable. An additional advantage is that they can be computed relative to a thresholded image without first finding an edge thereby avoiding the difficulties typically present in thinning and orientation determination.