基於邊緣資訊之策略性錯誤藏匿

Strategic Error Concealment Method Based on Edge Information

賴廷昆(Ting-Kun Lai)

指導教授 ： 張隆紋

國立清華大學/電機資訊學院/資訊工程學系/碩士(2010年)

摘要

在現今時日下，探討影像傳輸在容易發生錯誤的頻道裡是不可或缺的課題。隨著高比率視訊壓縮標準(如H264和MPEG4)的普及，高畫質視訊已是現在即時影像的趨勢。然而，一旦封包遺失發生，將會產生嚴重的錯誤傳播。為了解決這個問題，我們必須使用錯誤藏匿技術，根據遺留的時間域和空間域資訊來重建遺失的資料。
在本論文，我們提出了基於賽局理論的錯誤藏匿方法，賽局理論幫助我們從兩種區塊模式中選出較佳的一方來修補遺失的宏塊。視覺品質是本賽局的報酬，我們可由PSNR值來量化視覺品質，而計算時間則是本賽局的成本。我們在有限的計算時間的限制下產生最佳的視覺品質。我們使用遺失宏塊的邊緣資訊作為判斷採用時間域錯誤藏匿或空間域錯誤藏匿的重要準則。在適當選擇錯誤藏匿技術的情形下，我們可以在計算時間和視覺品質之間取得一個很好的平衡。

關鍵字

錯誤藏匿 ； 時間域 ； 空間域 ； 賽局理論

並列摘要

The transmission of video stream over the error-prone channel is an indispensable subject to discuss in the present days. With the widespread of high-ratio video compression standard (such as H264/MPEG-4 AVC), high-definition video is the latest trend of real-time video stream. However, once the packet loss happened, it can cause serious error propagations during the transmission process. To solve this problem, we need to use the error concealment techniques, which utilize the information of remaining spatial and temporal relatively, to reconstruct the corrupted data.
In our thesis, we introduce a game theoretic error concealment structure. Game theory is helpful in choosing the best strategy from two block modes for the lost macroblocks. The visual quality is the payoff in this game, which is evaluated from the PSNR (peak signal to noise ratio) value, and the computational time is the cost. We produce the best visual quality under the constraint of limited time. Edge information reflects the complexity of a region in a frame. We can use it as the criterion to make decision between temporal error concealment and spatial error concealment. With proper selection of error concealing method, we can have a good balance between the visual quality and the computational time.

並列關鍵字

h264 ； error concealment ； game theory ； spatial ； temporal

參考文獻

[2] Tung-Hsing Wu, Guan-Lin Wu, Ching-Yi Chen, Shao-Yi Chien, “Enhanced Temporal Error Concealment Algorithm with Edge-Sensitive Processing Order,” IEEE International Symposium on Circuits and Systems, 2008, pp. 3466-3469, 2008.

[3] Yanling Xu, Yuanhua Zhou, Tongji Univ, “Adaptive Temporal Error Concealment Scheme for H.264/AVC Video Decoder,” IEEE Transactions on Consumer Electronics, vol. 54, pp. 1846 – 1851, 2008.

[4] Xiaoyu Deng, Yi Liu, Chaoqun Hong, Jiajun Bu, Chun Chen, “A TEMPORAL ERROR CONCEALMENT ALGORITHM FOR H.264/AVC BASED ON EDGE DIRECTIONS,” IEEE International Conference on Image Processing, pp. 941 – 944, 2009.

[5] Zhao Weibin, Zhou Zhiheng, Xu Zhiliang, “Error Concealment for Video Sequences Based on Sobel Edge Detector,” International Conference on Communications, Circuits and Systems, 2008, pp. 723-726, 2008.

[6] Yue Shi, Xuhui Zhu, Jun Xia, Hanchun Yin, “A Fast and Efficient Spatial Error Concealment for Intra-coded Frames,” Congress on Image and Signal Processing, vol. 1, pp.264 – 267, 2008.