Using Optical Separable Wavelet Transform to Construct Oriented Optical Filter

Based on the cascade algorithm and the theory of 2-D separable wavelet transform, 2-D approximations of scaling and wavelet basis functions are computed and used in optical wavelet transform. The optical transform using these separable wavelet bases can be called optical separable wavelet transform. And the selection of mother wavelets is extended. Unlike 2-D discrete separable wavelet transform, optical separable wavelet transform does not have limitation on direction selectivity. Linearly combining multiple directional channels as a superposition filter, the transform of these bases can be fulfilled simultaneously and the transform results can be synthesized on the output plane. In this paper, 2-D scaling and wavelet basis functions of a biorthogonal wavelet, bior2.6, are calculated. Four directional channels combine into an oriented optical filter to increase the extracted feature energy in high frequency band. And simulation results are presented.