Image denoising using bivariate wavelet packet zerotrees and neighbor dependency

This paper presents image denoising methods performed within wavelet domain scheme by using wavelet packet zerotrees, and at the same time incorporating neighbor and inter-subband dependencies through NeighShrink and BiShrink [1] shrinkage functions, respectively. In particular, we call our proposed method as adaptive wavelet bivariate maximum a posteriori estimator (MAP) with NeighShrink threshold function namely, MAP_NBShrink_WP. In our second method, adaptive wavelet bivariate minimum mean square error estimator (MMSE) with NeighShrink threshold function, namely MMSE_NBShrink_WP, is proposed for image-denoising. Experimental results show that our proposed methods, MAP_NBShrink_WP and MMSE_NBShrink_WP, have better PSNR than BiShrink [1], NeighShrink [6] and BayeShrink [3] in oscillatory images (such as Barbara).