Construction of 2-D directional filter bank by cascading checkerboard-shaped filter pair and CMFB

• Published in: Signal processing Vol. 88; no. 10; pp. 2500 - 2510
• Main Authors: Zhou, Zuo-feng, Cheng, Yuan-yuan, Shui, Peng-lang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2008; Elsevier Science
• Subjects: Applied sciences; Checkerboard-shaped filter pair (CSFP); Cosine modulated filter bank (CMFB); Detection, estimation, filtering, equalization, prediction; Directional filter bank (DFB); Directional-frequency selectivity; Exact sciences and technology; Image denoising; Image processing; Information, signal and communications theory; Miscellaneous; Signal and communications theory; Signal processing; Signal, noise; Telecommunications and information theory; Directional filter bank (DFB); Checkerboard-shaped filter pair (CSFP); Cosine modulated filter bank (CMFB); Directional-frequency selectivity; Image denoising; Performance evaluation; Mobile radiocommunication; Image texture; GSM system; Subband decomposition; Image processing; Tensor product; Redundancy; Noise reduction; Wireless telecommunication; Selectivity; Algorithm; Cosine modulated filter bank (CMFB);Checkerboard-shaped filter pair (CSFP);Directional filter bank (DFB);Directional-frequency selectivity;Image denoising; Image segmentation; Signal processing; Filter bank
• ISSN: 0165-1684; 1872-7557; 1872-7557
• DOI: 10.1016/j.sigpro.2008.04.011

In this paper, we propose a new approach to construct a 2-dimensional (2-D) directional filter bank (DFB) by cascading a 2-D nonseparable checkerboard-shaped filter pair and 2-D separable cosine modulated filter bank (CMFB). Similar to diagonal subbands in 2-D separable wavelets, most of the subbands in 2-D separable CMFBs, tensor products of two 1-D CMFBs, are poor in directional selectivity due to the fact that the frequency supports of most of the subband filters are concentrated along two different directions. To improve the directional selectivity, we propose a new DFB to realize the subband decomposition. First, a checkerboard-shaped filter pair is used to decompose an input image into two images containing different directional information of the original image. Next, a 2-D separable CMFB is applied to each of the two images for directional decomposition. The new DFB is easy in design and has merits: low redundancy ratio and fine directional-frequency tiling. As its application, the BLS-GSM algorithm for image denoising is extended to use the new DFBs. Experimental results show that the proposed DFB achieves better denoising performance than the methods using other DFBs for images of abundant textures.