基于二次模型的运动估计快速算法设计

Novel Motion Estimation Algorithms Based on Quadratic Prediction

摘要: 本文提出了一种HEVC视频编码的运动估计快速算法，该算法可以显著加速搜索过程，编码效率与HEVC参考软件(Test Model)中的Test Zone Search (TZSearch)平分秋色。较之H.264/AVC视频标准，HEVC引入了更为复杂的混合编码框架和更大尺寸的搜索窗口，从而带来了更高的计算复杂度。为了降低复杂度，我们提出了一种新的运动估计算法，该算法仅利用搜索窗中所选取的少量几个点建立二次曲面模型，通过对像素的绝对差值和(SAD)分布的迭代分析，逐步缩小搜索范围，直到得出最优的运动矢量。该算法可被用于不同的编码环境中，实验结果表明，与HM相比，该算法可以节约大约40%的运动估计算法时间，仅引起轻微的性能损失。

Abstract: This paper presents a motion estimation (ME) algorithm for High Efficiency Video Coding (HEVC), which provides a strategy to speed up the search process significantly, while yielding the same quality performance as the Test Zone Search (TZSearch) scheme in HEVC Test Model (HM). Compared with the H.264/AVC, HEVC employs a more complex hybrid coding architecture and a larger size search window, leading to great computational complexity. In order to reduce the complexity, a novel motion estimation algorithm is proposed, in which some limited pixels of certain position in the current search window are utilized to build a quadratic model, and then shrink the search range repeatedly by analyzing the sum of absolute difference (SAD) distribution until the best motion vector (MV) is obtained. The proposed algorithm can be applied to various encoding conditions. Experimental results show that our method can save 40% of computations compared with the HM, with negligible decrease of coding quality.