A class of directional filter banks [image processing applications]

In this paper, we introduced a class of directional filter banks (DFB) having the previously proposed uniform DFB (uDFB) as a special case. The new DFBs implement a multiresolution and multidirection decomposition of images, while remaining perfect reconstruction (PR) and maximally decimated. We also discussed the permissible property of the filter banks in cases of being implemented by a tree structure and by direct implementation. The result shows that only one DFB in the class, which we call the quincunx uDFB, has the permissibility when being implemented directly by an eight-channel filter bank. Finally, an efficient tree structure for implementation of the quincunx uDFB is proposed.