A new type of feature extraction of patterns using coherent optical system

Abstract Fraunhofer diffraction of a two dimensional pattern possesses some useful properties in relation to pattern recognition. In the present paper, those properties are given with respect to use for feature extraction of patterns. A new type of spatial filtering method named “θ-Fourier Method” which extracts some features of patterns on the Fraunhofer diffraction plane is proposed, Moreover, some practical performances of this method are also experimentally investigated.