Subband adaptive regularization method for removing blocking effect

Abstract

This paper presents two new approaches to remove blocking effect in low-bit rate transform coded images by using 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 characteristic of each subband to bound the maximum tolerable error and the smoothness of the restored images in restoring subband images with regularization. One of them will also utilize the spatial activity of the restoring images to tighten the bounds. Computer simulations showed that the new adaptive objective functions could achieve a better restoration performance in terms of both subjective and objective measures than did other conventional objective functions.