Abstract
The block DCT (BDCT) is by far one of the most popular transforms used in image and video coding. However, it introduces a noticeable blocking artifact at low data rates. A great deal of work has been done to remove the artifact with information extracted from the spatial and frequency domains. In this paper we address the video sequence restoration problem as a 3D Huber-Markov random field model and derive the temporal extension to traditional maximum a posteriori (MAP)-based methods. Two schemes, we call temporal MAP (TMAP) and motion compensated TMAP (MC-TMAP) respectively, are presented. We test our methods on MPEG-2 compressed sequences and evaluate their performances with traditional MAP restoration. Experimental results confirm that our schemes can significantly improve the visual quality of the reconstructed sequences.
Keywords
Markov processes, data compression, discrete cosine transforms, image restoration, image sequences, maximum likelihood decoding, motion compensation, transform coding, video coding 3D Huber-Markov random field model, BDCT, MC-TMAP, MPEG-2 compressed sequences, block DCT, blocking artifact, maximum a posteriori-based methods, motion compensated TMAP, performance, post processing, reconstructed sequences, temporal MAP, video coding, video sequence restoration, video sequences, visual quality
