Subband adaptive regularization method for removing blocking effect

This paper presents two new approaches to removing the blocking effect in low-bit rate transform coded images by using a subband decomposition/reconstruction technique. They are designed to act as a supplementary post-processing step of the JPEG standard. Both approaches make use of the noise characteristics of each subband to bound the maximum tolerable error and the smoothness of the restored images in restoring the subband images by regularization. In one method the spatial activity of the restored images is also used to tighten the bounds. Computer simulations show that the new adaptive objective functions could achieve a better restoration performance in terms of both subjective and objective measures than other conventional objective functions