c++ - 使用 RANSAC 估计两组点之间的二维变换

Question

据我所知，OpenCV 使用 RANSAC 来解决 findHomography 的问题，它返回一些有用的参数，例如 homograph_mask。

但是，如果我只想估计 2D 变换，这意味着仿射矩阵，有没有办法使用与 findHomography 相同的方法，它使用 RANSAC 并返回该掩码？

Answer 1

您可以直接使用 estimateAffinePartial2D : https://docs.opencv.org/4.0.0/d9/d0c/group__calib3d.html#gad767faff73e9cbd8b9d92b955b50062d

cv::Mat cv::estimateAffinePartial2D (   
    InputArray  from,
    InputArray  to,
    OutputArray     inliers = noArray(),
    int     method = RANSAC,
    double  ransacReprojThreshold = 3,
    size_t  maxIters = 2000,
    double  confidence = 0.99,
    size_t  refineIters = 10 
)   

例如:

        src_pts = np.float32([pic1.key_points[m.queryIdx].pt for m in matches]).reshape(-1, 1, 2)
        dst_pts = np.float32([pic2.key_points[m.trainIdx].pt for m in matches]).reshape(-1, 1, 2)

        # Find the transformation between points, standard RANSAC
        transformation_matrix, mask = cv2.findHomography(src_pts, dst_pts, cv2.RANSAC, 5.0)

        # Compute a rigid transformation (without depth, only scale + rotation + translation) and RANSAC
        transformation_rigid_matrix, rigid_mask = cv2.estimateAffinePartial2D(src_pts, dst_pts)