图像的区域描述方法及运动估计

文中提出一种任意形状区域的图像描述方法进行图像序列的运动估计。首先，对初始帧图像采用保边界平滑，然后，对平滑帧进行分水岭分割。根据标记图像，将图像以区域邻接图的方式进行存储。为解决过度分割的问题，给出了区域的灰度特性和边界强度及区域尺寸相结合的融合准则。最后，每个区域采用仿射运动模型及非线性最小均方法进行参数优化。得到的运动矢量场同基于像素点的估计方法相比具有更高的一致性和抗干扰性，运动补偿差图像的峰值信噪比得以提高。

Region-based image representation and motion estimation

An image representation method based on arbitrary shaped regions is proposed in this paper, and the motion estimation of the image sequence is executed according to this representation. The initial frame is smoothed while edge of the image is preserved. The smoothing algorithm is the modification version of Alvarez's method. The smoothed frame is segmented by the watershed method. According to the marker image, the image is stored in the form of region adjacency graph. To solve the problem of the over-segmentation, the criterions of region intensity and edge strength and region size are combined. The affine transformation is used as motion model for each region, and the nonlinear least squares method is used for the optimization. Compared with the method based on pixel, the result shows that the motion vectors produced by this method are more consistent and robust and the PSNR is improved.