Extract face coordinates from upsampled image using Frontal Face Detector about dlibdotnet HOT 4 CLOSED

static void Main(string[] args)
{
    using var original = Dlib.LoadBmp<RgbPixel>("Lenna.bmp");
    using var image = Dlib.LoadBmp<RgbPixel>("Lenna.bmp");
    using var faceDetector = Dlib.GetFrontalFaceDetector();
    using var pyr = new PyramidDown(2);
    var upsamplingAmount = 1;

    var levels = upsamplingAmount;
    while (levels > 0)
    {
        levels--;
        Dlib.PyramidUp(image);
    }

    var rects = faceDetector.Operator(image);

    foreach (var rectangle in rects)
        Dlib.DrawRectangle(original, rectangle, new RgbPixel(255, 0, 0));

    foreach (var t in rects)
    {
        var rect = pyr.RectDown(t, (uint)upsamplingAmount);
        Dlib.DrawRectangle(original, rect, new RgbPixel(0, 255, 0));
    }
    
    Dlib.SavePng(original, "result.png");
}