新一代的國際視訊壓縮標準，其名稱為H.264，而在H.264最重要的一個部分移動估測(motion estimation)中，採用了多幅參考畫面(multiple reference frames)、可變區塊大小(variable block size)、移動向量(motion vector)可搜尋至四分之一像素精確度(quarter pixel resolution)等新的壓縮技術，由於這些具有吸引力的特徵，可使得預測更為精確且擁有更高的壓縮效率。然而也因為這些特徵，使得H.264移動估測的複雜度與運算量大幅的提升。因此近幾年中，許多快速且有效率來降低H.264中移動估測複雜度的演算法研究一直是個熱門的研究話題。而在本論文中，根據移動向量分佈的特徵，提出了二種快速整數點移動搜尋演算法來降低H.264移動估測過程中的複雜度與運算量。實驗結果顯示，本論文所提出的二種快速整數點移動搜尋演算法，可以大幅度的減少所需的平均搜尋點數，且同時還能將影像品質保持在一定的水準之上。 H.264 is a new international video coding standard. Many novel techniques are adopted in motion estimation of H.264 . It basically includes the motion vector at quarter pixel resolution with variable block sizes and multiple reference frames. With these attractive characteristics, it can achieve more accurate prediction and higher compression efficiency. However, because of these characteristics, the complexity and computation load of motion estimation increase greatly in H.264. Many fast and efficient methods to reduce the complexity of motion estimation are always hot research spot in recent years. Depending on the characteristics of motion vector distribution, we propose two fast integer pixel motion estimation algorithms to reduce the computation cost in H.264. The experiment results show that the proposed algorithms can reduce more average search point and maintain coding performance.
