A Bayesian approach for the estimation and transmission of regularization parameters for reducing blocking artifacts

With block-based compression approaches for both still images and sequences of images annoying blocking artifacts are exhibited, primarily at high com pression ratios. They are due to the independent processing (quantization) of the block transformed values of the intensity or the displaced frame dif ference. In this paper, we propose the application of the hierarchical Baye sian paradigm to the reconstruction of block discrete cosine transform (BDC T) compressed images and the estimation of the required parameters. We deri ve expressions for the iterative evaluation of these parameters applying th e evidence analysis within the hierarchical Bayesian paradigm. The proposed method allows for the combination of parameters estimated at the coder and decoder. The performance of the proposed algorithms is demonstrated experi mentally.