c++opencvslam-algorithm

opencv vector<point3f> to 3 column mat

I have 2 vectors (p1 and p2) of point3f variables which represent 2 3D pointclouds. In order to match these two point clouds I want to use SVD to find a transformation for this. The problem is that SVD requires a matrix (p1*p2 transpose). My question is how do I convert a vector of size Y to a Yx3 matrix?

I tried cv::Mat p1Matrix(p1) but this gives me a row vector with two dimensions.I also found fitLine but I think this only works for 2D.

Thank you in advance.

Solution

  • How about something like:

    cv::Mat p1copy(3, p1.size(), CV_32FC1);

for (size_t i = 0, end = p1.size(); i < end; ++i) {
    p1copy.at<float>(0, i) = p1[i].x;
    p1copy.at<float>(1, i) = p1[i].y;
    p1copy.at<float>(2, i) = p1[i].z;
}

    If this gives you the desired result, you can make the code faster by using a pointer instead of the rather slow at<>() function.