Blocking artifacts are serious artifacts caused by block-based hybrid video coding

and significantly impair the subjective quality of the compressed video. In this paper

the fundamental reasons of blocking artifacts are explored

based on which an effective quantization method for DCT coefficients for reducing blocking artifacts is proposed. The proposed method adjusts the quantization process to reduce the variation of the quantization error at block edges

which increases the correlation of the quantization error of adjacent blocks and therefore reduces the blocking artifacts of the compressed video. Experimental results have demonstrated the effectiveness of the proposed method in reducing blocking artifacts and improving the subjective quality of video frames. Furthermore

the proposed method is practical in implementation since it has a low computational complexity and is compatible with video coding standards.