一种具有仿射不变性的倾斜影像快速匹配方法

摘要

This paper proposed a quick,affine invariance matching method for oblique images.It calculated the initial affine matrix by making full use of the two estimated camera axis orientation parameters of an oblique image,then recovered the oblique image to a rectified image by doing the inverse affine transform,and left over by the SIFT method.We used the nearest neighbor distance ratio(NNDR), normalized cross correlation(NCC)measure constraints and consistency check to get the coarse matches, then used RANSAC method to calculate the fundamental matrix and the homography matrix.And we got the matches that they were interior points when calculating the homography matrix,then calculated the average value of the matches’principal direction differences.During the matching process,we got the initial matching features by the nearest neighbor (NN)matching strategy,then used the epipolar constrains,homography constrains,NCC measure constrains and consistency check of the initial matches’ principal direction differences with the calculated average value of the interior matches’principal direction differences to eliminate false matches.Experiments conducted on three pairs of typical oblique images demonstrate that our method takes about the same time as SIFT to match a pair of oblique images with a plenty of corresponding points distributed evenly and an extremely low mismatching rate.%提出了一种较为快速且具有仿射不变性的倾斜影像匹配方法.通过估算影像的相机轴定向参数计算出初始仿射矩阵，通过逆仿射变换得到纠正影像，对纠正影像进行 SIFT 匹配.首先利用比值提纯法(NNDR)、归一化互相关(NCC)测度约束和左右一致性检验得到粗匹配点对，由粗匹配点对利用RANSAC方法计算出基本矩阵F 和单应矩阵H.匹配时，匹配策略采用最邻近匹配，并利用极线约束、单应矩阵约束、NCC测度约束和主方向差值一致性约束剔除误匹配.通过对三组典型的倾斜影像数据进行试验，试验表明该方法匹配准确率高，匹配点对较为密集、均匀，且效率较高.