臺灣博碩士論文加值系統

視訊編碼利用去除相鄰畫面間冗贅而達到壓縮的效果。對於一般較低動態的視訊畫面其特點為連續畫面間大多由呈現靜止或緩慢移動的背景或物體所構成，在傳統視訊壓縮方法下耗費過多空間在儲存用來重建低動態物件以及靜止背景的移動向量(Motion Vector)上。我們提出的方法將相鄰並有相似移動向量的巨集區塊(Macroblock)合併為較大的矩形區塊，這些較大的矩形區塊可被視為部份或整塊呈現靜止狀態的背景或物體，而各個矩形區塊於重建時只需要一個移動向量。實驗結果顯示，我們的方法與固定區塊大小的傳統方法在移動向量的儲存空間利用率上提高將近50％。

This thesis presents a new motion vector coding scheme based on bottom-up macroblock merging procedure. For low motion video sequences, most of the storage space of the motion vector data spending on the low motion objects or stills background. The proposed scheme merges the neighboring macroblocks with similar motion vectors into bigger rectangular blocks, and those merged blocks may represent as all or a part of the objects and the background. For the merged blocks, each block will need only one motion vector to reconstruct it. Experimental re-sults show that the proposed scheme can reduce about 50% motion vector coding bits as com-pared to the conventional way of storing motion vectors for each macroblock.

摘要 i
Abstract ii
Contents iii
List of Tables iv
List of Figures v
1. Introduction 1
2. Related work 3
2.1. Quadtree structured region-wise motion compensation 3
2.2. Fast motion estimation based on motion vector homogeneity 3
2.3. Dictionary-based image compression 4
2.4. An efficient intermode decision algorithm based on motion homogeneity 5
3. Motion vector coding scheme based on bottom-up macroblock merging procedure 8
3.1. Bottom-up macroblock merging procedure 8
3.2. Candidate block decision procedure 10
3.3. Motion vector encoding 13
3.4. Motion vector decoding 13
4. Experimental results 14
4.1. Comparison with the conventional fixed block size coding scheme 14
4.2. Comparison with the efficient intermode decision algorithm 19
5. Conclusion and future work 23
6. References 24

[1]Hanan A. Mahmoud and Magdy Bayoumi, “An Efficient Low-Bit Rate Motion Compensa-tion Technique Based on Quadtree,” IEEE International Conference on Multimedia and Expo, pp.213-216, July 2000.

[2]Iain E. G. Richardson, “H.264 and MPEG-4 Video Compression: Video Coding for Next Generation Multimedia,” Wiley, August 2003.

[3]Jiajun Zhang, M. Omair Ahmad, and M. N. S. Swamy, “Quadtree Structured Region-Wise Motion Compensation for Video Compression,” IEEE Transactions on Circuits and Systems for Video Technology, vol. 9, pp.808-822, August 1999.

[4]Kai-Chung Hou, Mei-Juan Chen, and Ching-Ting Hsu, “Fast Motion Estimation by Motion Vector Merging Procedure for H.264,” IEEE International Conference on Multimedia and Expo, Amsterdam, Netherlands, pp.1444-1447, July 2005.

[5]Libo Yang, Keman Yu, Jiang Li, and Shipeng Li, “An Effective Variable Block-Size Early Termination Algorithm for H.264 Video Coding,” IEEE Transactions on Circuits and Sys-tems for Video Technology, vol.15, pp.784-788, June 2005.

[6]Nathanael J. Brittain and Mahmoud R. El-Sakka, “Grayscale true two-dimensional dictio-nary-based image compression,” Journal of Visual Communication and Image Representa-tion, vol. 18, no. 1, pp.35-44, February 2007.

[7]Shou-Yi Tseng, “Motion estimation using a frame-based adaptive thresholding approach,” Real-Time Imaging, vol. 10, no. 1, pp.1-7, February 2004.

[8]Shen-Chuan Tai, Ying-Ru Chen, and Sheng-Jia Li, “Low complexity variable-size block-matching motion estimation for adaptive motion compensation block size in H.264,” IEEE Asia-Pacific Conference on Circuits and Systems, pp.613-616, December 2004.

[9]Thomas Wiegand, Gary J. Sullivan, Gisle Bjøntegaard, and Ajay Luthra, “Overview of the H.264/AVC Video coding Standard,” IEEE Transaction on Circuits and Systems for Video Technology, vol. 13, pp.560-576, July 2003.

[10]Zhi Liu, Liquan Shen, and Zhaoyang Zhang, “An Efficient Intermode Decision Algorithm Based on Motion Homogeneity for H.264/AVC,” IEEE Transaction on Circuits and Systems for Video Technology, vol.19, pp.128-132, January 2009.

[11]Zhi Zhou, Ming-Ting Sun, and Yuh-Feng Hsu, “Fast variable block-size motion estimation algorithm based on merge and split procedures for H.264/MPEG-4 AVC,” Proceeding of IEEE International Symposium on Circuits and Systems, vol. 3, pp. 725-728, May 2004.