Modified Quantization Constraint Set for Deblocking Transform Coded Images

At low bit rates, the block discrete cosine transform (BDCT) compression methods often give rise to blocking artifacts. In both enhancement and restoration approaches to the problem, quantization constraint set (QCS) is widely used as a priori information about the coding process. In this paper, we propose a modified constraint set based on the statistical property of quantization errors. The experimental results show that the extension can be effective. While combined with other algorithms, the proposed QCS outperforms traditional QCS and produces results comparable with the state of the art in the literature.