利用运动强度判据的高效自适应运动估计算法

摘要

为减少运动估计计算量,提高视频编码效率,提出了基于运动强度的自适应运动估计搜索算法.该算法通过定义运动强度概念来反映帧间图像运动的剧烈程度,依据当前帧的运动强度信息预测下一帧运动情况,并自适应选择算法进行运动搜索:当运动强度高于设定阈值时选用UMHexagonS算法,低于该阈值时选用改进的六边形算法.实验仿真结果表明,该算法能在保证图像质量和压缩效果的基础上,大幅提高编码效率,并可通过调节阈值大小满足不同编码要求.%In order to reduce the complexity of motion estimation and improve the efficiency of the video encoder, an adaptive motion estimation search algorithm based on motion intensity is proposed. Motion intensity reflects the intensity of motion between adjacent frames. By defining the concept of motion intensity, the movement of the next frame is predicted based on the measured intensity information of the current frame, and a different motion search algorithm is selected adaptively. If the motion intensity of the current frame is greater than the threshold, the UMHexagonS search algorithm is chosen, otherwise the improved hexagon search algorithm is chosen. Simulation results show that the coding efficiency is improved significantly, while the image quality and compression performance change little. In addition, the threshold of motion intensity in the algorithm is adjustable, thus the demands of different encoding can be met by changing the threshold.