Objective image quality measure for block-based DCT coding

Block-based discrete cosine transform (DCT) coding has been widely adopted in image/video compression standards, such as JPEG and MPEG. Such coding will produce a noticeable artifact known as the blocking effect at very low bit rate applications. In the literature, there have been various postprocessing methods proposed to reduce the blocking effect. However, there is no suitable objective criterion evaluating the effectiveness of these various methods. This paper presents a new objective measure evaluating the postprocessing methods. The proposed measure also provides an analytical result on the underlying sources of artifacts.