Post-processing for artifact reduction in JPEG-compressed images

An iterative post-processing algorithm for reducing blocking and ringing in block transform-coded images is presented. It smooths the decompressed image and uses convex projections theory to preserve the image´s edges and bit-stream. The algorithm exploits the coding scheme´s block structure and ringing behavior. In experiments it outperforms an existing method and gives significant subjective and objective improvement over the decompressed image. Sufficient conditions for algorithm convergence are given