The Importance Of Spatial Frequency And Orientation In Image Decomposition And Coding
E. Shlomot, Y.Y. Zeevi, William A. Pearlman · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1987
A scheme is proposed for image decomposition into components having spatial frequency band and orientation selectivity characteristic of the visual system. The Hexagonal-discrete-Fourier-transform (HDFT) of an hexagonally sampled image is partitioned into 36 bands, each of one octave and 30 degrees of angular orientation. Computational results of such image decomposition exhibit self-similarity of edge distribution, along the pyramidal structure of the spatial frequency components, in each of the six orientations. A combination of coding scheme, which reduces the apparent redundancy, and efficient bit reallocation procedure achieves good image reconstruction with data transmission rate of about 1.0 bits/pixel.