Model-based smoothing for reducing artifacts in compressed images

Blocking artifacts often appear in compressed images coded by the block discrete cosine transform. The paper presents a smoothing method for reducing those artifacts. The method is based on adjusting pixel intensities of a blocky image to values determined by a smooth model image. Certain points in the blocky image are selected to construct a triangular mesh. The mesh forms the model image. The adjusted image is further subject to a narrow quantization constraint. The method produces superior images in terms of subjective quality and objective quality when compared to existing methods. It is fast, since no iterations are required.