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Hi, I am trying to calculate eigenvectors but I am getting huge eigenvalues. As result, I am getting vector component 0. It will be great if you suggest the way.

int main() { Mat img = Mat::zeros(500, 500, CV_8U); ellipse(img, RotatedRect(Point(250, 250), Size(300, 200), 30), 255, FILLED);

Moments m = moments(img, true);
Point p(m.m10 / m.m00, m.m01 / m.m00);

double u20 = ((m.m20 / m.m00) - (p.x * p.x));
double u02 = ((m.m02 / m.m00) - (p.y * p.y));
double u11 = ((m.m11 / m.m00) - (p.x * p.y));

double angle = 0.5 * atan((2 * u11) / ( u20 - u02));
double eigenValue1 = 0.5 * (u20 + u02) + 0.5 * sqrt((4 * u11 * u11) + (u20 - u02) * (u20 - u02));
double eigenValue2 = 0.5 * (u20 + u02) - 0.5 * sqrt((4 * u11 * u11) + (u20 - u02) * (u20 - u02));

double a[2][2] = {{ u20 - eigenValue1, u11 }, { u11, u02 - eigenValue1 } };

double b[2][1] = { { 0 }, { 0 } };

Mat A = Mat(2, 2, CV_32FC1, a);
Mat B = Mat(2, 1, CV_32FC1, b);

Mat v = A.inv() * B;
cout << "v= " << endl << " " << v << endl;
waitKey(0);
return 0;

}

Hi, I am trying to calculate eigenvectors but I am getting huge eigenvalues. As result, I am getting vector component 0. It will be great if you suggest the way.

int main()
{
    Mat img = Mat::zeros(500, 500, CV_8U);
    ellipse(img, RotatedRect(Point(250, 250), Size(300, 200), 30), 255, FILLED);
 
FILLED);

    Moments m = moments(img, true);
 Point p(m.m10 / m.m00, m.m01 / m.m00);

 double u20 = ((m.m20 / m.m00) - (p.x * p.x));
 double u02 = ((m.m02 / m.m00) - (p.y * p.y));
 double u11 = ((m.m11 / m.m00) - (p.x * p.y));

 double angle = 0.5 * atan((2 * u11) / ( u20 - u02));
 double eigenValue1 = 0.5 * (u20 + u02) + 0.5 * sqrt((4 * u11 * u11) + (u20 - u02) * (u20 - u02));
 double eigenValue2 = 0.5 * (u20 + u02) - 0.5 * sqrt((4 * u11 * u11) + (u20 - u02) * (u20 - u02));

 double a[2][2] = {{ u20 - eigenValue1, u11 }, { u11, u02 - eigenValue1 } };

 double b[2][1] = { { 0 }, { 0 } };

 Mat A = Mat(2, 2, CV_32FC1, a);
 Mat B = Mat(2, 1, CV_32FC1, b);

 Mat v = A.inv() * B;
 cout << "v= " << endl << " " << v << endl;
 waitKey(0);
 return 0;
}
  
}