OpenCV Camera Calibration, Assertion Failed <ni > 0 && ni==ni1> - c++

Question

I am trying to perform camera calibration using openCV. On the same example data from openCV samples this works great, but my source generates an error:
Assertion failed <ni > 0 && ni==ni1>... collectCallibrationData.. calibration.cpp line 3193"
objectPoints and imagePoints are the same size. Changing other inputs dont affect error code.
Can anyone help me deal with it? The code follows:
void main()//enter code here
{
//initial operations, declatarions etc
int *Asize; float *APoints;
float AAPoints[]= {/* My Array */};
int AAsize[] = {4,54,2}; //My array size
Asize = AAsize; APoints = AAPoints; // will be called as dll that is why this wierd attribution
int page = *(Asize); int row = *(Asize+1); int col = *(Asize +2);
Point3f pointBuf;
vector<vector<Point3f>> imagePoints;
vector<Point3f> vectBuf;
Size boardSize;
boardSize.height = 6; boardSize.width = 9;
Mat cameraMatrix, distCoeffs;
float squareSize=50;
//change 1d array to vector<vector<point3f>>
for (int i = 0; i<page; i++)
{
for (int j = 0; j<row; j++)
{
pointBuf.x = *(APoints + (i*(row*col))+j*2);
pointBuf.y = *(APoints + (i*(row*col))+j*2+1);
pointBuf.z = 0;
vectBuf.push_back(pointBuf);
}
imagePoints.push_back(vectBuf);
vectBuf.clear();
}
// create objectPoint vector<vector<Points3f>>
vector<vector<Point3f>> objectPoints;
vectBuf.clear();
for( int i = 0; i < boardSize.height; ++i )
{
for( int j = 0; j < boardSize.width; ++j )
vectBuf.push_back(Point3f(float( j*squareSize ), float( i*squareSize ), 0));
}
objectPoints.resize(imagePoints.size(),vectBuf);
//initialize starting variables for calibration
cameraMatrix = Mat::eye(3, 3, CV_64F);
distCoeffs = Mat::zeros(1, 1, CV_64F);
cameraMatrix.at<double>(0,0) = 1.0;
vector<Mat> rvecs, tvecs;
Size imageSize; imageSize.width = 2040; imageSize.height = 2040;
double rms = calibrateCamera(objectPoints, imagePoints, imageSize, cameraMatrix, distCoeffs, rvecs, tvecs);
}

Answer 1

There is a trouble with the use of cv::calibrateCamera(). It requires std::vector<std::vector<cv::Point3f>> as the first argument and std::vector<std::vector<cv::Point2f>> as the second.
e.g.:
cv::Size imageSize(2040, 2040);
cv::Mat cameraMatrix, distCoeffs;
std::vector<cv::Mat> rvecs, tvecs;
std::vector<std::vector<cv::Point2f> > imagePoints;
std::vector<std::vector<cv::Point3f> > objectPoints;
// Fill imagePoints and objectPoints
...
cv::calibrateCamera(objectPoints, imagePoints, imageSize, cameraMatrix, distCoeffs, rvecs, tvecs);

Answer 2

I met the same issue, too. In my case, there is a bug to convert vector< vector < Point3f > > to InputArrayOfArrays.
You may run the following sample code to check it in your system.
using namespace std;
using namespace cv;
/** #function main */
int main( void )
{
vector<Point3f> objectPoints_tmp(54);
objectPoints_tmp.clear();
for( int i = 0; i < 9; ++i )
for( int j = 0; j < 6; ++j )
objectPoints_tmp.push_back(Point3f(j*50, i*50, 0.0f));
vector<vector<Point3f> > objectPoints(7, objectPoints_tmp);
InputArrayOfArrays OBJPOINT = objectPoints; std::cout << (int) OBJPOINT.total() << std::endl;
for( int i = 0; i < 7; ++i )
std::cout << OBJPOINT.getMat(i).checkVector(3, CV_32F) << std::endl;
waitKey(0);
return 0;
}
Normally, it should print out
7
54
54
54
54
54
54
54
In my NG case, it prints out random numbers.
I guess that the opencv lib is not fit with my system(win7 x64 + vs2012). After rebuild opencv myself, it may work now. You may google keyword "Win7x64 VS2012 OpenCV CMake TBB".