标题: | 變動取樣率之低功率移動估測設計 On Power-Saving Motion Estimation using Variable Subsample Ratios |
作者: | 葉松樹 Sung-Shu Yeh 董蘭榮 Lan-Rong Dung 電控工程研究所 |
关键字: | 取樣率;低功率;移動估測;影像壓縮;Subsample;Motion Estimation;Power-Saving;H.264/MPEG-4 AVC |
公开日期: | 2004 |
摘要: | 最新的影像壓縮規格中,如MPEG-1,MPEG-2,MPEG-4 and H.264/MPEG-4 AVC,移動位移估測需要龐大的計算量與能量消耗。因此,移動位移估測主導了在影像壓縮中的計算量與能量需求。針對位移估測,很多論文已經提出了不同的快速演算法,可是他們並沒有考慮到影像內容的影響。所以,我們提出了一種新的快速演算法,稱為“變動取樣率之低功率位移估測演算法”,這個演算法可以針對不同性質的影像內容,選取最適合的取樣率來完成位移估測,以達到節省能量且畫質衰退在可以容許的範圍之內。針對不同性質的影像內容,動態的選擇四組不同的取樣率,分別為16:16、16:8、16:4、16:2。我們提出的這個演算法已經成功的實現在H.264/MPEG-4 AVC的軟體模型JM9.2中,實驗結果顯示這個演算法不只可以動態的依照不同的影像內容來選擇適合的取樣率,而且可以維持最多0.36 dB的畫質衰退,在固定的傳輸頻率下,平均可以節省69.9%的能量損失。這個演算法的另一個好處是可以輕易的與其他位移估測快速演算法結合,而達到進一步減少所需的計算量,我們結合JM9.2中的FME快速演算法,可以維持最多0.33 dB的畫質衰退且節省73.6%的能量損失。因此,對於我們所提出的“變動取樣率之低功率位移估測演算法”,是適合實現在高畫質的即時影像壓縮應用上。 In modern video standard, such as MPEG-1, MPEG-2, MPEG-4 and H.264/MPEG-4 AVC, motion estimation requires the heaviest computational load and hence dominates main power requirement in video compression. Lots of published papers have presented efficient algorithms for motion estimation. But they don’t consider the influence of the video content. An adaptive motion estimation algorithm with variable subsample ratios has been presented. This proposed algorithm can adaptively select the compatible subsample ratio for each current group of picture (GOP). This proposed algorithm has been successful implemented in H.264/MPEG-4 AVC with software model JM9.2. Experimental results have shown that the proposed algorithm can not only adaptively select the suitable subsample ratio to various video sequences but also maintain ΔPSNRY of 0.36 dB at most to save about 69.6% power consumption of motion estimation in a fixed bit rate control on average. The proposed algorithm can also easily combine with other fast algorithms which reduce the computational complexity of FSBM. For FME in JM 9.2, we save 73.6% power consumption and keep quality degradation under 0.33 dB. Hence the proposed algorithm is suitable for real-time implementation of high quality and power-saving video applications using a powerful CPU. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT009212520 http://hdl.handle.net/11536/68157 |
显示于类别: | Thesis |
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