模型基编码的运动参数估计及误差准则

在人脸序列的图像编码中 ,模型基编码方法可以获得高的主观图像质量和低的码率 ,而受到广泛重视。但是 ,其运动参数的可靠估计还是一个难点 ,而且也没有一个较好的适合视觉特性的误差准则。本文提出了基于特征点的运动参数估计算法 ,并根据边沿 ,亮度和端点特性来自动提取特征点及自适应调整点的数目。提出用重建的图像的质量来估价运动参数误差 ,并给出了误差面积和轮廓转折率误差二个函数。这二个函数较好地反映了运动参数误差引入的图像几何失真。

Motion parameters estimation and error criteria in model-based coding

Model based facial image coding has got extensive attention due to its high subject image quality and low bit rates.But the estimation of object motion parameters is still a difficult problem,and there are no proper error criteria for the quality assessment satisfied with visual properties.This paper presents a motion parameters estimation algorithm based on feature points.The feature points are automatically extracted from edge,brightness and end node points,and the numbers of feature point are adjusted adaptively.A method of estimation of motion parameter error based on the quality of reconstructed image is suggested.That area error and contour transition turn error is used to be quality criteria.The two functions reflect the image geometric distortion caused by motion parameter error properly.