在这段视频中，当球进入画面时，我很难捕捉到

http://www.youtube.com/watch?v=x1V6_OHrXIo

我也不知道要设置什么参数，而且尝试随机值似乎根本没有帮助，我看不到模式来知道数字有什么影响。这就是我正在尝试的。

背景减法或颜色检测不起作用，因为它们很容易改变。我需要一个更通用的解决方案。

var laneSixBedRect = new Rectangle(new Point(240, 185), new Size(240, 150));
var laneSixBed = imgSource.GetSubRect(laneSixBedRect);

TrackShot(laneSixBed);

private static void TrackShot(Image<Bgr, byte> laneBed)
{
    var laneBedGray = laneBed.Convert<Gray, byte>();

    var circles = laneBedGray.HoughCircles(
        new Gray(150),  //cannyThreshold
        new Gray(75),   //circleAccumulatorThreshold
        2.0,            //Resolution of the accumulator used to detect centers of the circles
        20.0,           //min distance 
        5,              //min radius
        50              //max radius
        )[0];           //Get the circles from the first channel

    foreach (CircleF circle in circles)
        laneBed.Draw(circle, new Bgr(Color.Brown), 2);
}

编辑：这是我的 currentTrackShot 方法，它的准确率大约为 70%，仍然有一些误报，还有一些漏报。

    private static void TrackShot(Rectangle laneRect, Image<Bgr, byte> prevImage, Image<Bgr, byte> currImage, Image<Bgr, byte> background)
    {
        var laneBedBack = background.GetSubRect(laneRect);
        var laneBedPrev = prevImage.GetSubRect(laneRect);
        var laneBedCurr = currImage.GetSubRect(laneRect);

        var laneBedBackGray = laneBedBack.Convert<Gray, byte>();
        //TODO: Should these be Smoothed?
        var laneBedPrevGray = laneBedPrev.Convert<Gray, byte>().SmoothGaussian(5);
        var laneBedCurrGray = laneBedCurr.Convert<Gray, byte>().SmoothGaussian(5);

        //TODO: Uncomment to see difference between frames, nearly black when no motion
        //var diff = laneBedPrevGray.AbsDiff(laneBedCurrGray);
        //diff.Convert<Bgr, byte>().CopyTo(laneBedCurr);

        //TODO: Improve these values
        var prevFeatures = laneBedPrevGray.GoodFeaturesToTrack(100, .01, .1, 3)[0];

        var returnFeatures = new PointF[1];
        byte[] status;
        float[] trackError;
        OpticalFlow.PyrLK(laneBedPrevGray, laneBedCurrGray, prevFeatures, new Size(15, 15), 5, new MCvTermCriteria(5), out returnFeatures, out status, out trackError);

        //TODO: Now how do I refine this???
        for (var i = 0; i < returnFeatures.Length; i++)
        {
            var prevPoint = prevFeatures[i];
            var currPoint = returnFeatures[i];
            var state = status[i];
            var error = trackError[i];

            var line = new LineSegment2D(new Point((int)prevPoint.X, (int)prevPoint.Y), new Point((int)currPoint.X, (int)currPoint.Y));
            if (state == 1 && line.Length > 15 && error < 10)
            {
                laneBedCurr.Draw(line, new Bgr(Color.Green), 3);
                Console.WriteLine("E: {0}", error);
                Console.WriteLine("L: {0}", line.Length);
            }
        }

        viewerModified.Image = currImage;
    }

EDIT2：我的终极目标是能够沿着球的轨迹画一条线，并以某种可以与其他方式进行比较的方式存储该轨迹。