opencv - 多 View 几何

Question

我从两台相同品牌的相机拍摄的两张图像相距一定距离，拍摄相同的场景。我想计算两个相机之间的真实世界旋转和平移。为了实现这一点，我首先提取了两个图像的 SIFT 特征并匹配它们。

我现在有了基本矩阵以及单应矩阵。然而无法进一步进行，很多困惑。谁能帮我估计两个相机之间的旋转和平移？

我正在使用 OpenCV 进行特征提取和匹配、单应性计算。

Answer 1

如果你有单应性，那么你也有旋转。一旦你有了单应性，就很容易得到旋转和平移矩阵。

例如，如果您使用的是 OpenCV c++:

param[in] H
param[out] pose
void cameraPoseFromHomography(const Mat& H, Mat& pose)
{
    pose = Mat::eye(3, 4, CV_32FC1);      // 3x4 matrix, the camera pose
    float norm1 = (float)norm(H.col(0));  
    float norm2 = (float)norm(H.col(1));  
    float tnorm = (norm1 + norm2) / 2.0f; // Normalization value

    Mat p1 = H.col(0);       // Pointer to first column of H
    Mat p2 = pose.col(0);    // Pointer to first column of pose (empty)

    cv::normalize(p1, p2);   // Normalize the rotation, and copies the column to pose

    p1 = H.col(1);           // Pointer to second column of H
    p2 = pose.col(1);        // Pointer to second column of pose (empty)

    cv::normalize(p1, p2);   // Normalize the rotation and copies the column to pose

    p1 = pose.col(0);
    p2 = pose.col(1);

    Mat p3 = p1.cross(p2);   // Computes the cross-product of p1 and p2
    Mat c2 = pose.col(2);    // Pointer to third column of pose
    p3.copyTo(c2);       // Third column is the crossproduct of columns one and two

    pose.col(3) = H.col(2) / tnorm;  //vector t [R|t] is the last column of pose
}

此函数根据包含旋转的单应性计算相机位姿。如需进一步的理论信息，请关注此 thread .