適用於H.264之高效率圖框間編碼機制

有別於傳統的視訊壓縮標準，H.264視訊壓縮標準在動作補償上允許採用超過單張的參考圖框，加上H.264採用了複雜的可變區塊大小動作補償技術，更將巨幅地增加編碼端最佳框間編碼的運算複雜度。因此，本論文提出一個參考圖框的挑選機制，此機制可挑選出部份的參考圖框，並僅就此部份圖框來進一步作可變區塊大小的動作估測。而在可變區塊大小動作估測方面，我們則提出一個快速區塊模式決斷機制來降低其運算複雜度。此外，我們更引進一個動作搜尋範圍的動態控制機制來加速已決定區塊模式之下的動作估測。本論文所提到的參考圖框挑選機制、區塊模式決斷機制以及動作搜尋範圍的動態控制機制都是建立在簡單的8x8區塊模式動作估測上。我們的演算法優點之一是可與傳統單張參考圖框上既有的任一個動作搜尋演算法互相結合。實驗結果顯示我們所提出的演算法雖然簡單卻十分有效率。

關鍵字

H.264 ；多參考圖框動作估測；可變區塊大小動作估測；參考圖框挑選；區塊模式決斷

並列摘要

Unlike the traditional video codec, H.264 permits more than one reference frame in motion estimation. Complicated by the variable block size motion estimation, it would take up a significant encoding complexity to find the best inter coding. Thus, in this thesis, we propose a reference frame selector to choose only a subset of reference frames for taking a step further to the variable block size motion estimation. And the complexity of the variable block size motion estimation is reduced by introducing a fast block mode decision. Moreover, we bring in a dynamic search range controller to further speed up the motion search of the decided modes. All of the reference frame selection, block mode decision and search range control are based on the result of a simple test on 8x8 motion search. One advantage of our proposed mechanism is to be able to work with any existing motion search algorithms developed for the traditional single reference frame. The experiment results show that our proposed algorithm is simple yet effective.

並列關鍵字

H.264 ； multiple reference frame motion estimation ； variable block size motion estimation ； reference frame selection ； block mode decision

參考文獻

[4] L.M. Po and W.C. Ma, "A novel four-step search algorithm for fast block motion estimation," IEEE Trans. Circuits Syst. Video Technol., vol. 6, no. 3, June 1996, pp. 313-317.

[5] S. Zhu and K.K. Ma, "A new diamond search algorithm for fast block-matching motion estimation," IEEE Trans. Image Processing, vol. 9, no. 2, Feb. 2000, pp. 287-290.

[6] C. Zhu, X. Lin, L.P. Chau, K.P. Lim, H.A. Ang, and C.Y. Ong, "A novel hexagon-based search algorithm for fast block motion estimation," in Proc. IEEE Int. Conf. Acoustics, Speech, and Signal Processing, vol. 3, May 2001, pp. 1593-1596.

[7] C. Zhu, X. Lin, L.P. Chau, and L.M. Po, "Enhanced hexagonal search for fast block motion estimation," IEEE Trans. Circuits Syst. Video Technol., vol. 14, no. 10, Oct. 2004, pp. 1210-1214.

[8] Z. Chen, P. Zhou, and Y. He, "Fast Integer Pel and Fractional Pel Motion Estimation for JVT," ITU-T Q6/SG16, Doc#JVT-F017, 5-12 Dec. 2002.

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適用於H.264之高效率圖框間編碼機制

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