A blocking artifacts reduction algorithm via the bilateral filter in DCT domain

In this paper, a novel blocking artifacts reduction algorithm for low-bit-rate compressed images is proposed. The proposed algorithm adaptively adjusts Discrete Cosine Transform (DCT) coefficients of the shifted blocks to remove the significant blocking artifacts. Then, the bilateral filter is introduced to smooth the subject DCT blocks. The subject DCT block is predicted via the weighted average of overlapping neighboring blocks in DCT domain. The weights are determined according to both the similarity between the subject coded block and the spatial distance of the overlapped neighboring blocks. Image fidelity has been further improved via a quantization constraint. Experimental results illustrated that the proposed method achieves better results in both subjective and objective quality.