Adaptive wavelet threshold for image denoising by exploiting inter-scale dependency

Abstract

An inter-scale adaptive, data-driven threshold for image denoising via wavelet soft-thresholding is proposed. To get the optimal threshold, a Bayesian estimator is applied to the wavelet coefficients. The threshold is based on the accurate modeling of the distribution of wavelet coefficients using generalized Gaussian distribution (GGD), and the near exponential prior of the wavelet coefficients across scales. The new approach outperforms BayesShrink because it captures the statistical inter-scale property of wavelet coefficients, and is more adaptive to the data of each subband. Simulation results show that higher peak-signal-to-noise ratio can be obtained as compared to other thresholding methods for image denoising. © Springer-Verlag Berlin Heidelberg 2007.