Point object type
Another very common class template is Point. This class defines a 2D point specified by its coordinates x and y.
Like Point, there is a Point3 template class for 3D point support.
Like the Vec class, OpenCV defines the following Point aliases for our convenience:
typedef Point_<int> Point2i;
typedef Point2i Point;
typedef Point_<float> Point2f;
typedef Point_<double> Point2d;
The following operators are defined for points:
pt1 = pt2 + pt3;
pt1 = pt2 - pt3;
pt1 = pt2 * a;
pt1 = a * pt2;
pt1 = pt2 / a;
pt1 += pt2;
pt1 -= pt2;
pt1 *= a;
pt1 /= a;
double value = norm(pt); // L2 norm
pt1 == pt2;
pt1 != pt2;