Research On In-Loop Filter Algorithm For H.264/AVC

With the development of Internet and network transmission, various kinds of new multimedia service arise, which demand a higher performance of image/video coding techniques. Block-based hybrid coding is the main structure of current and near future video coding. With the increase of the compression ratio, the subjective quality of video images will be degraded greatly. Fortunately, the deblocking filter can reduce blocking artifacts effectively, thus will improve the subject quality significantly.This paper aims to deeply study the whole framework of H.264 and deblocking filter technology. At first, a brief introduction of the standard and main coding tools is presented, and then the prototype of the system of H.264 based on JM is given. Secondly, a detailed introduction and analysis of the in-loop deblocking filter adopted in H.264 is described. To further improve the performance of in-loop filter algorithm, a novel in-loop filter algorithm with multi-modes is proposed. According to the peculiar coding information in H.264, block boundaries are divided into different filter modes, and a corresponding filter technology is adopted for each mode. Experimental results show that the proposed method can remove more blocking artifacts, which greatly improves subjective image quality. Finally, a fast in-loop deblocking filter based on content pre-determination is proposed, which utilizes STGS-image as an effective and efficient criterion to adaptively determine the block edge strength. Results of simulation experiments illustrate the performance in reducing the complexity of deblocking filter. The experiment indicates the validity and the feasibility of the proposed algorithm.