OpenCV Error: Camera Calibration: Assertion failed in matrix_wrap.cpp - c++

Question

The Error:
OpenCV(3.4.1) Error: Assertion failed (i < 0) in cv::debug_build_guard::_InputArray::getMat_,
file C:\build\master_winpack-build-win64-vc15\opencv\modules\core\src\matrix_wrap.cpp, line 50
The Code inside "matrix_wrap.cpp" that triggers the Error:
if( k == STD_VECTOR )
{
CV_Assert( i < 0 );
int t = CV_MAT_TYPE(flags);
const std::vector<uchar>& v = *(const std::vector<uchar>*)obj;
return !v.empty() ? Mat(size(), t, (void*)&v[0]) : Mat();
}
Entire Code:
#include <iostream>
#include <opencv2/opencv.hpp>
int main(int argc, char *argv[])
{
cv::Mat img = cv::imread(argv[1], CV_LOAD_IMAGE_GRAYSCALE);
cv::Size imageSize = cv::Size(img.size[0], img.size[1]);
cv::Mat cameraMatrix, distCoeffs;
double squareSize = 30;
cv::Size boardSize = cv::Size(6, 11);
std::vector<cv::Point2f> imagePoints;
std::vector<cv::Point3f> objectPoints;
for (int i = 0; i < boardSize.height; i++) {
for (int j = 0; j < boardSize.width; j++) {
objectPoints.push_back(
cv::Point3f(float(j * squareSize), float(i * squareSize), 0));
}
}
std::vector<cv::Mat> rvecs, tvecs;
bool found = false;
if (img.size[0] > 1)
{
bool found = findChessboardCorners(img, boardSize, imagePoints, cv::CALIB_CB_ADAPTIVE_THRESH);
if (found)
{
drawChessboardCorners(img, boardSize, imagePoints, found);
}
objectPoints.resize(imagePoints.size(), objectPoints[0]);
double rms = calibrateCamera(objectPoints, imagePoints, imageSize, cameraMatrix, distCoeffs, rvecs, tvecs);
cv::namedWindow("My Image");
cv::imshow("My Image", img);
cv::waitKey(1000);
}
return 0;
}
I want to use a basic camera calibration with a straigth chessboard.
Until the function "calibrateCamera" everything works fine, but I can't figure out why this Error shows up.
The size of "objectPoints" and "imagePoints" is the same.
Thank you in advance.
P.S.:
I'm new in this forum and also in OpenCV ;)

Answer 1

As per this source of opencv, lines 3139 and 3142 :
CV_Error(CV_StsUnsupportedFormat, "objectPoints should contain vector of vectors of points of type Point3f");
CV_Error(CV_StsUnsupportedFormat, "imagePoints1 should contain vector of vectors of points of type Point2f");
the types for objectPoints and imagePoints should be std::vector<std::vector<Point{2|3}f>>