public Mat OnCameraFrame(CameraBridgeViewBase.ICvCameraViewFrame inputFrame)
    {
        Mat input = inputFrame.Rgba();
        List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
        Mat gray = new Mat();
        //Mat hierarchy = new Mat();
        Imgproc.CvtColor(p0: input, p1: gray, p2: Imgproc.ColorRgb2gray);
        Mat blur = new Mat();
        Imgproc.GaussianBlur(gray, blur, new Size(7, 7), -2);
        Mat thresh = new Mat();
        Imgproc.Threshold(blur, thresh, 127, 250, Imgproc.ThreshBinary);
        Mat edged = new Mat();
        Imgproc.Canny(thresh, thresh, 25, 50);
        Imgproc.Dilate(thresh, thresh, new Mat(), new Point(-1, 1), 1);
        Mat hierarchy = thresh.Clone();
        Imgproc.FindContours(hierarchy, contours, new Mat(),
             Imgproc.RetrExternal, Imgproc.ChainApproxNone);
        Java.Lang.JavaSystem.Out.Println("contours" + contours);
        if (contours != null)
        {
                Java.Lang.JavaSystem.Out.Println("found contours");
            for (int i = 0; i < contours.Count(); i++)
            {
                Imgproc.DrawContours(input, contours, i, new Scalar(255, 0, 0), -1);
            }

        }
        else
        {
            Java.Lang.JavaSystem.Out.Println("no contours");
        }
        return input;

List<MatOfPoint> contours = new ArrayList<MatOfPoint>();

IList<MatOfPoint> contours = new JavaList<MatOfPoint>();