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In this thesis, a post-processing deblocking filter is proposed to reduce the blocking effects. This proposed algorithm is suitable for the current block-based video standards without any modification. The proposed algorithm uses Sobel operator and wavelet transform to accurately detect blocking effects at 4×4 or 8×8 blocking boundaries automatically. In the filtering stage, the proposed algorithm provides four filter modes to eliminate blocking effects at different color regions according to human color vision and color psychology analysis. Experimental results show that the proposed algorithm has better subjective and objective qualities for H.264/AVC reconstructed video sequences compared with several existing methods.

CHAPTER 1 Introduction …………………………………………………………..1
1.1 Overview of Video Coding …………………………………………………1
1.2 What are Blocking Effects …………………………………………………5
1.3 Motivation ………………………………………………………………….7
1.4 The Organization of the Thesis …………………………………………….9
CHAPTER 2 Review of Related Deblocking Filter Algorithms …………………..10
2.1 Previous Works in Deblocking Filter …………………………………….10
2.2 Deblocking Methods for Video Coding ………………………………….12
2.3 Deblocking Filter for H.264 ……………………………………………...13
2.3.1 Boundary Strength ………………………………………………...14
2.3.2 Boundaries Filtering ………………………………………………16
2.4 Low Complexity Deblocking Method for DCT Coded Video Signal ……19
2.5 Post-Processing Deblocking Filter Algorithm for Various Video
Decoders ………………………………………………………………………..25
CHAPTER 3 Proposed Blocking Artifacts Detection ……………………………..33
3.1 Sobel Operator ……………………………………………………………35
3.2 Wavelet Transform ……………………………………………………….39
3.3 Combination of Sobel Operator and Wavelet Transform ………………...45
3.4 Results of Blocking Artifacts Detection ………………………………….48
CHAPTER 4 Proposed Deblocking Artifacts Algorithm ………………………….53
4.1 Human Vision System and Color Psychology …………………………...55
4.1.1 Human Vision System …………………………………………….55
4.1.2 Color Psychology …………………………………………………57
4.2 Filtering Stage ……………………………………………………………59
4.2.1 Complex Mode ……………………………………………………59
4.2.2 R、G、B Mode …...........................................................................61
CHAPTER 5 Experimental Results ……………………………………………….65
5.1 Objective Measurement …..........................................................................67
5.2 Experimental Results of H.264/AVC Video ……………………………...71
5.2.1 Subjective Quality Comparison ......................................................71
5.2.2 Objective Quality Comparison ........................................................81
5.3 Computational Complexity Comparison ....................................................85
CHAPTER 6 Conclusions and Future Work ............................................................87
6.1 Conclusion ..................................................................................................87
6.2 Future Work ………………………………………………………………89
Bibliography …………………………………………………………………………90

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