I want to use cv::sfm::triangulatePoints from opencv_contrib in OpenCV 3.2.0. I get following error:
OpenCV Error: Assertion failed
(points2d_tmp[i].rows == 2 &&
points2d_tmp[i].cols == n_points) in
triangulatePoints, file
/home/kozuch/install/opencv_contrib-3.2.0/modules/sfm/src/triangulation.cpp, line 140 terminate called after
throwing an instance of
'cv::Exception' what():
/home/kozuch/install/opencv_contrib-3.2.0/modules/sfm/src/triangulation.cpp:140:
error: (-215) points2d_tmp[i].rows ==
2 && points2d_tmp[i].cols == n_points
in function triangulatePoints
Here is my code:
vector<cv::Point2f> points1, points2;
featureDetection(img1, points1); // my custom function
featureTracking(img1,img2,points1,points2); // my custom function
vector<vector<cv::Point2f> > sfmPoints2d;
sfmPoints2d.push_back(points1);
sfmPoints2d.push_back(points2);
//~ cv::Mat matFeatures1(points1);
//~ cv::Mat matFeatures2(points2);
//~ matFeatures1 = matFeatures1.t(); // transpose - change rows for columns
//~ matFeatures2 = matFeatures2.t();
//~ vector<cv::Mat> sfmPoints2d;
//~ sfmPoints2d.push_back(matFeatures1);
//~ sfmPoints2d.push_back(matFeatures2);
vector<cv::Mat> sfmProjMats;
sfmProjMats.push_back(projMat0);
sfmProjMats.push_back(projMat1);
cv::Mat points3d;
cv::sfm::triangulatePoints(sfmPoints2d, sfmProjMats, points3d);
sfmPoints2d does the porblem. I tried to use Mats instead of inner vectors but the error remained the same. Even tried to transpose the Mats (change rows for cols). The docs here say:
points2d - Input vector of vectors of 2d
points (the inner vector is per
image). Has to be 2 X N.
projection_matrices - Input vector with
3x4 projections matrices of each
image.
points3d - Output array with computed 3d points. Is 3 x N.
Can someone tell me what am I doing wrong?
FOUND AND AN ANSWER (can not post real answer so putting it here):
Found the solution finally (the matrices in the top should be ideally empty).
cv::Mat points1Mat = (cv::Mat_<double>(2,1) << 1, 1);
cv::Mat points2Mat = (cv::Mat_<double>(2,1) << 1, 1);
for (int i=0; i < points1.size(); i++) {
cv::Point2f myPoint1 = points1.at(i);
cv::Point2f myPoint2 = points2.at(i);
cv::Mat matPoint1 = (cv::Mat_<double>(2,1) << myPoint1.x, myPoint1.y);
cv::Mat matPoint2 = (cv::Mat_<double>(2,1) << myPoint2.x, myPoint2.y);
cv::hconcat(points1Mat, matPoint1, points1Mat);
cv::hconcat(points2Mat, matPoint2, points2Mat);
}
vector<cv::Mat> sfmPoints2d;
sfmPoints2d.push_back(points1Mat);
sfmPoints2d.push_back(points2Mat);
vector<cv::Mat> sfmProjMats;
sfmProjMats.push_back(projMat0);
sfmProjMats.push_back(projMat1);
cv::Mat points3d;
//~ cout << "matFeatures1 = " << endl << " " << matFeatures1 << endl << endl;
cv::sfm::triangulatePoints(sfmPoints2d, sfmProjMats, points3d);
