基于HEVC的亚像素运动估计快速算法

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0.043 dB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。

Fast sub pixel motion estimation algorithm based on HEVC

An improved fast sub pixel search algorithm is proposed based on the characteristic of the matching 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.