基于HEVC的亚像素运动估计快速算法

Fast sub-pixel motion estimation algorithm based on HEVC

利用在亚像素搜索区域内误差匹配函数以单峰曲面分布的特点,提出了一种改进的亚像素的快速搜索算法。根据整像素搜索的结果建立5点的误差曲面模型,估计1/2像素最佳点的位置,并确定1/2像素点搜索范围和搜索模板;再根据1/2像素搜索结果确定1/4像素点的搜索方式,完成亚像素搜索。实验表明,算法在峰值信噪比平均下降0.043dB的条件下,减少了亚像素搜索部分近60%的计算量,在保证重建图像的主观质量和客观质量的同时,提高了编码效率。

An improved fast sub-pixel search algorithm is proposed based on the characteristic of the matc-hing error function with the single peak error surface.Firstly,a best half-pixel position is approximated by a five point error surface model based on the results of the integer-pixel motion estimation,and then the search range and search template are determined for the half-pixel.Secondly,a search method of the quarter-pixel is selected according to the half-pixel search results to complete the sub-pixel search.The experimental results show that the proposed algorithm can reduce nearly 60%of the calculation in the sub-pixel search with averagely a 0.043 dB decrease of peak signal to noise ratio,which improves the coding efficiency while guaranteeing the subjective and objective quality of the reconstructed image.