Adaptive deblocking algorithm based on image characteristics for low bit-rate video

Abstract

Reconstructed images in low bit-rate video coding often have visually annoying artifacts, such as blocking artifacts and corner outliers, usually due to block-based quantization and motion-compensated prediction. In this paper, we propose an adaptive deblocking algorithm based on local image characteristics. We remove ringing artifacts using a simple low-pass filter in the preprocessing. Among four filtering modes, an appropriate filter is selected adaptively, removing noticeable blocking artifacts in flat areas, while preserving details without blurring in highly complex areas. The proposed filter contains a non-symmetric filter a corner outlier removal filter. Simulation results show the effectiveness of the proposed deblocking algorithm in objective and subjective quality compared with those of the MPEG-4 deblocking filter.