static {		
		try {
			NativeLoader.loadLibrary(Core.NATIVE_LIBRARY_NAME);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

/**
	 * 发现轮廓
	 * @param image
	 * @param onBlank
	 * @return
	 */
    static List<MatOfPoint> find_contours(Mat image, boolean onBlank) {
        Mat imageBW = new Mat();

        Imgproc.cvtColor(image, imageBW, Imgproc.COLOR_BGR2GRAY);
        Imgproc.Canny(imageBW,imageBW,100.0,300.0,3, true);

        List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
        Imgproc.findContours(imageBW, contours, new Mat(), Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_NONE);
        return contours;

    }

static Scalar BLACK = new Scalar(0,0,0) ;
	/**
	 * 绘制轮廓
	 * @param originalMat
	 * @param contours
	 * @param thickness
	 * @return
	 */
    static Mat draw_contours(Mat originalMat, List<MatOfPoint> contours, int thickness) {
        Mat target =
          new Mat(originalMat.height(), originalMat.width(), CvType.CV_8UC3, WHITE);

        for (int i = 0; i < contours.size(); i++)
            Imgproc.drawContours(target, contours, i, BLACK, thickness);

        return target;
    }

/**
 * 发现及绘制轮廓
 * @param args
 */
public static void main(String[] args) {
	
	Mat kittens = imread("images/three_black_kittens.jpg");
	List<MatOfPoint> contours = find_contours(kittens, true);

      Mat target = draw_contours(kittens, contours, 7);
      imwrite("output/kittens-contours-7.png", target);

      Mat masked = mask_on_bg(target, "images/light-blue-gradient.jpg");
      imwrite("output/kittens-masked.png", masked);

      target = draw_contours(kittens, contours, 3);
      imwrite("output/kittens-contours-3.png", target);
}

static Mat mask_on_bg(Mat mask, String backgroundFilePath) {
        Mat target = new Mat(mask.height(),mask.width(),CvType.CV_8UC3,WHITE);
        Mat bg = imread(backgroundFilePath);
        Imgproc.resize(bg, bg, target.size());
        bg.copyTo(target, mask);
        return target;
    }