A FILTER BANK FOR THE DIRECTIONAL DECOMPOSITION OF IMAGES - THEORY AND DESIGN

This paper introduces a directionally oriented 2-D filter bank with the property that the individual channels may be critically sampled without loss of information. The passband regions of the component filters are wedge shaped and thus provide directional information. It is shown that these filter bank outputs may be maximally decimated to achieve a minimum sample representation in a way that permits the original signal to be exactly reconstructed. The paper discusses the theory for directional decomposition and the issues associated with maximum decimation and reconstruction. In addition, implementation issues are addressed where realizations based on both recursive and nonrecursive filters are considered.