OpenCV::solvePNP() - Assertion failed

Question

I am trying to get the pose of the camera with the help of solvePNP() from OpenCV.

After running my program I get the following errors:

OpenCV Error:         


        

Answer 1

I run in exactly the same problem with solvePnP and opencv3. I tried to isolate the problem in a single test case. I seams passing a std::vector to cv::InputArray does not what is expected. The following small test works with opencv 2.4.9 but not with 3.2.

And this is exactly the problem when passing a std::vector of points to solvePnP and causes the assert at line 63 in solvepnp.cpp to fail !

Generating a cv::mat out of the vector list before passing to solvePnP works.

//create list with 3 points
std::vector vectorList;
vectorList.push_back(cv::Point3f(1.0, 1.0, 1.0));
vectorList.push_back(cv::Point3f(1.0, 1.0, 1.0));
vectorList.push_back(cv::Point3f(1.0, 1.0, 1.0));

//to input array
cv::InputArray inputArray(vectorList);
cv::Mat mat = inputArray.getMat();
cv::Mat matDirect = cv::Mat(vectorList);

LOG_INFO("Size vector: %d mat: %d matDirect: %d", vectorList.size(), mat.checkVector(3, CV_32F), matDirect.checkVector(3, CV_32F));

QVERIFY(vectorList.size() == mat.checkVector(3, CV_32F));

Result opencv 2.4.9 macos:

TestObject: OpenCV
Size vector: 3 mat: 3 matDirect: 3

Result opencv 3.2 win64:

TestObject: OpenCV
Size vector: 3 mat: 9740 matDirect: 3