一种仿射不变量支持的准稠密控制点匹配算法

待配准的两景影像之间存在非均匀形变时，需要采用非刚性模型进行校正，而密集的、均匀分布的控制点是构建非刚性模型的基础，对此提出一种仿射不变量支持的准稠密控制点匹配算法。首先从两景影像提取特征点并进行稀疏匹配，根据稀疏匹配点消除两景影像间的整体偏移；然后以稀疏匹配点作为三角形的顶点，迭代构建特征点间的近邻三角形，并以面积之比作为仿射不变量，据此判断三角形顶点之间是否满足匹配关系，实现匹配点传播，从而获得准稠密的匹配点集；最后采用HJ-Landsat数据与南极地区Landsat 7 ETM+数据进行实验，结果表明，本文方法能够提取均匀分布的准稠密控制点，在提取率等指标方面优于对比方法。

An Affine Invariant-based Match Propagation Method for Quasi-dense Image Registration

Non-rigid models are needed to correct the non-uniform deformation between two images; dense, uniformly distributed control points is the premise of constructing such non-rigid models. This paper puts forward an affine invariant-based match propagation method for quasi-dense image registration. Interest points are extracted from the input image and reference image, respectively; and sparsely matched. According to the sparsely matched points, the global offset between the two images is estimated and corrected. A corresponding adjacent triangle is established using the interest points in the two images interactively; and an affine invariant, the ratio of the triangle area, is employed to determine whether the vertices in the two triangles match or not. Through this method, the spare initial seed matching points propagate to other points of interest to obtain quasi-dense match. The HJ-Landsat image and ETM+ data of Antarctic data are taken in an experiment, the results show that our method can extract dense and uniformly distributed matching points while outperforming other state of art methods in true positive ratio.