快速鲁棒的全局运动估计算法

对全局运动估计算法进行研究,提出一种新的快速且鲁棒性较好的全局运动估计算法.全局运动估计是MPEG-4中的sprite编码中的关键技术,其性能将直接影响编码效率和速度.所提出的算法比传统的Levenberg-Marquadet方法要快,而且参数估计比较准确.新算法是基于非线性密度进行估计的,采用了六参数的仿射模型.为了提高计算速度,采用了3层金字塔进行多分辨率计算,而且在每层迭代计算中都抽取重要的特征点进行计算,同时结合了Gauss-Newton优化计算方法.为了保证计算的准确性,采用基于直方图和基于块两

A Fast and Robust Algorithm of Global Motion Estimation

In this paper, the algorithm of global motion estimation is investigated, and a new algorithm for fast global motion estimation is introduced. Global motion estimation is the key problem in sprite coding, which is adopted in MPEG-4 compression standard. The proposed new algorithm is much faster than the traditional Levenberg Marquadet algorithm, but the estimated result of the new algorithm is more accurate. The new algorithm is based on nonlinear dense estimation and applies the affine model. In order to accelerate the algorithm, three-level pyramid is utilized in the calculation. It uses those important feature pixels in the calculation of every pyramid level, and combines Gauss-Newton algorithm. In order to guarantee the accuracy of the result, noise is effectively eliminated by histogram-based and block-based methods. Robust statistics is used in the calculation to reduce the influence of noise. The experimental results show that the new algorithm is superior to Levenberg-Marquadet algorithm.