Real And Positive Filter Based On Circular Harmonic Expansion

Carlos Ferreira; Javier Garcia; Enrique Tajahuerce

doi:10.1117/12.961630

25 October 1989 Real And Positive Filter Based On Circular Harmonic Expansion

Carlos Ferreira, Javier Garcia, Enrique Tajahuerce

Proceedings Volume 1134, Optical Pattern Recognition II; (1989) https://doi.org/10.1117/12.961630
Event: 1989 International Congress on Optical Science and Engineering, 1989, Paris, France

Abstract

A real and positive filter for pattern recognition is presented. The filter, based on the circular harmonic (CH) expansion of a real function, is partially rotation invariant. As it is real and positive, the filter can be recorded on a transparency as an amplitude filter. Computer simulations of character recognition show a partial rotation invariance of about 40°. Optical experiments agree with these results and with acceptable discrimination between different characters. Nevertheless, due to experimental difficulties, the method is onerous for use in general pattern recognition problems.

Citation Download Citation

Carlos Ferreira, Javier Garcia, and Enrique Tajahuerce "Real And Positive Filter Based On Circular Harmonic Expansion", Proc. SPIE 1134, Optical Pattern Recognition II, (25 October 1989); https://doi.org/10.1117/12.961630

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