Coding artifact reduction using adaptive post-treatment
This paper presents a post-processing method for reducing blocking and ringing artifacts resulting from lossy coding techniques based on the Discrete Cosine Transform (DCT) such as JPEG, H.261, H.263 or MPEG. These coding artifacts appear at low and medium bit rate and strongly affect the image quality. The proposed method is based on a constrained least-squares method using adaptive smoothing post-processing. The objective is to reduce blocking artifact and edge noise while preserving image details. To evaluate the visual image quality, a new blockiness visibility measure is proposed. The method has been tested on some degraded images and video sequences. The obtained results are satisfying and clearly demonstrate the efficiency of the proposed method.