Finally, the guided image filter is used to eliminate the blocking artifacts
induced by the dark channel and remove the halos caused by the DT-CWT, while preserving the edge information of the original image.
For adaptive sampling schemes, the block-variance based reconstructed image has obvious blocking artifacts
. And it is the same with the edge based reconstructed one, though it is more visually pleasant than block-variance based reconstructed one.
Performance analysis of latest H.264/AVC standard showed its significant coding gains and compression efficiency over existing video compression standards (Weigand et al., 2003; Raja and Mirza, 2004) However, during compression process, loss of correlation between adjacent blocks during quantization process results in visually disturbing artifacts called blocking artifacts.
Motion compensated prediction is another source of blocking artifacts in video.
Blocking artifacts are discontinuities caused by encoding at the block boundary of the reconstructed picture, and seriously affect the subjective quality of videos.
To reduce the impact of blocking artifacts on video quality, various filtering techniques have been developed.
The image deblocking method based on image enhancement does not consider the cause of blocking artifacts and only conducts image enhancement operation, such as spatial filtering ,  and frequency domain filtering , .
Therefore, blocking artifacts are reduced by these steps.
"Adaptive Post filtering of Transform coefficients for the Reduction of Blocking Artifacts", IEEE Transactions on Circuits and Systems Technology, 18(6): 594-601.
To reduce the blocking artifact, LF components are smoothened in the adjacent LF blocks and invalid HF components are discarded.
When the window size becomes large, blocking artifacts
(10) and effectively remove the blurring and blocking artifacts in edge and texture regions.
It can be seen that the proposed algorithm can remove the blurring and blocking artifacts around lap, and the better subjective visual quality is obtained.
Different from 8J-MCI proposed by , we use the overlapped blocks to interpolate the current frame in order to suppress blocking artifacts
. The results of simulation show that the proposed method is not only robust to motion vector estimated wrongly, but also can reduce blocking artifacts
The visibility strength of the blocking artifacts
for the horizontal direction ([V.sub.hor_blocking]) can be determined by averaging [S.sub.hor_visibility] over the block edge and intermediate positions as follows: