private void trackCamshift(Bgr <byte>[,] frame, Rectangle searchArea, out Gray <byte>[,] probabilityMap, out Box2D foundBox)
{
const int PROBABILITY_MIN_VAL = (int)(0.3f * Byte.MaxValue);
//convert to HSV
var hsvImg = frame.ToHsv();
//back-project ratio hist => create probability map
probabilityMap = ratioHist.BackProject(hsvImg.SplitChannels <Hsv <byte>, byte>(0, 1)); //or new Image<Gray<byte>>[]{ hsvImg[0], hsvImg[1]...}
//user constraints...
Gray <byte>[,] mask = hsvImg.InRange(new Hsv <byte>(0, 0, (byte)minV), new Hsv <byte>(0, 0, (byte)maxV), Byte.MaxValue, 2);
probabilityMap.AndByte(mask, inPlace: true);
//run Camshift algorithm to find new object position, size and angle
CentralMoments centralMoments;
foundBox = Camshift.Process(probabilityMap, searchArea, Meanshift.DEFAULT_TERM, out centralMoments);
//stopping conditions
float avgIntensity = centralMoments.Mu00 / (foundBox.Size.Area() + Single.Epsilon);
if (avgIntensity < PROBABILITY_MIN_VAL || foundBox.Size.IsEmpty || foundBox.Size.Height < 12)
{
foundBox = Box2D.Empty; //invalid box
}
}