An effective approach for wavelet lifting based on filter optimization and median operator

In JPEG2000, the Cohen–Daubechies–Feauveau (CDF) 9/7-tap wavelet filter implemented by using the conventional lifting scheme has two problems. The first problem is that the filter coefficients are remaining complex; second, the conventional lifting scheme ignores image edges in the coding process. In this article, we propose an effective wavelet lifting scheme to solve these problems. For this purpose, we design the optimal 9/7-tap wavelet filters in two steps. In the first step, we select the appropriate filter coefficients; in the second step, we employ a median operator to consider image edges. Experimental results from using the median lifting scheme and combining filter optimization and median lifting show that our proposed methods outperform the well-known CDF 9/7-tap wavelet filter of JPEG2000 on edge-dominant images. VC 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 359–366, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ima.20255