Nonuniform Directional Filter Banks With Arbitrary Frequency Partitioning
Nonuniform Directional Filter Banks With Arbitrary Frequency Partitioning
复制标题
DOI：
10.1109/tip.2010.2052267
复制
发表时间：
2011
影响因子：
10.6
通讯作者：
Lili Liang;Guangming Shi;Xuemei Xie
中科院分区：
文献类型：
--
作者：
Lili Liang;Guangming Shi;Xuemei Xie
方向滤波器组(DFBs)在图像的方向性表示中是非常需要的。在本文中，我们提出了一种二维非下采样非均匀方向滤波器组(NUDFB)及其设计方法。所提出的NUDFB具有非均匀的楔形子带，并且允许任意的频率划分方案。它可以根据图像的方向分布来提取方向信息。这一吸引人的优势是现有的定向变换无法实现的。所提出的NUDFB的设计方法是基于伪极傅里叶变换。利用伪极网格的几何性质，我们使用一维非下采样非均匀滤波器组来获得一组非均匀楔形子带。在设计过程中，只涉及一维运算，从而避免了在设计二维风扇滤波器时遇到的困难。为了说明该算法的潜力，文中给出了一个图像方向分解的例子。
Directional filter banks (DFBs) are highly desired in directional representation of images. In this correspondence, we propose a 2-D nonsubsampled nonuniform directional filter bank (NUDFB) and its design method. The proposed NUDFB has nonuniform wedge-shaped subbands and allows arbitrary frequency partitioning schemes. It can extract directional information according to the directional distribution of images. This attractive advantage cannot be achieved by the existing directional transforms. The design method of the proposed NUDFB is based upon the pseudopolar Fourier transform. By utilizing the geometry property of the pseudopolar grid, we employ a 1-D nonsubsampled nonuniform filter bank to obtain a set of nonuniform wedge-shaped subbands. During the design process, only 1-D operations are involved and, thus, the difficulty encountered in the design of 2-D fan filters is avoided. To demonstrate the potential of the proposed NUDFB, an example on image directional decomposition is given.