25 October 1989 Real And Positive Filter Based On Circular Harmonic Expansion
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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
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.
© (1989) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Carlos Ferreira, Carlos Ferreira, Javier Garcia, Javier Garcia, Enrique Tajahuerce, Enrique Tajahuerce, } "Real And Positive Filter Based On Circular Harmonic Expansion", Proc. SPIE 1134, Optical Pattern Recognition II, (25 October 1989); doi: 10.1117/12.961630; https://doi.org/10.1117/12.961630

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