I need draw circle with even number diameter (for example, 100 px).

If use cv::circle() or cv::ellipse() diameter always is odd number ;

In `ellipse()`

function you can define the bounding box of the ellipse (a `RotatedRect`

), which can have any size (even real numbers).

For example a circle with diameter=100:

`ellipse(image, RotatedRect(Point2f(100,100), Point2f(100,200), Point2f(200,200)), Scalar(0,0,255);`