A simple algorithm for removing blocking artifacts in block-transform coded images

Abstract

Despite their widespread popularity, the Joint Photographers Expert Group (JPEG) and Motion Pictures Expert Group (MPEG) compression standards can lead to noticeable "blocking" artifacts-artificial rectangular discontinuities in the decoded image. Powerful postprocessing algorithms have been developed to remove blocking artifacts without destroying key image information. However, all but the simplest algorithms can be too complex for real-time applications such as video and still image decoding. We introduce a fast, easy-to-implement algorithm that removes blockiness by performing a simple nonlinear smoothing of pixels. This approach significantly improves visual quality and achieves subjective and objective (PSNR) gains that are competitive with the best deblocking algorithms reported in the literature at much reduced computational complexity.