用安卓设备识别ArUco码

先来看下效果

静态图片中的ArUcon码识别

在之前程序的基础上再添加一个Button和TextView，点击“识别”按钮检测照片中的ArUco码后，在屏幕最下方显示识别到的ArUco的id和四个角点坐标，四个角点从左上角点开始顺时针计数。
还有些地方没有完善，不知道为什么识别过后颜色会变。因为还没有做校准、相机标定，所以红色的Z轴指向不正确。

    private void detectArUco() {

        Mat src = Imgcodecs.imread(imagePath);  //相册选的图
        Mat gray = new Mat();
        Imgproc.cvtColor(src, gray, Imgproc.COLOR_BGRA2GRAY);  //灰度处理

        Dictionary dictionary = Aruco.getPredefinedDictionary(Aruco.DICT_4X4_50);

        List<Mat> corners = new LinkedList<>();
        corners.clear();

        MatOfInt ids = new MatOfInt();

        DetectorParameters parameters;
        parameters = DetectorParameters.create();

        Aruco.detectMarkers(gray, dictionary, corners, ids, parameters);

        if (corners.size() > 0) {

            double[] id = ids.get(0, 0);
            double id0 = id[0];
            String sid0 = Double.toString(id0);

            Mat corner1 = corners.get(0);

            double a[] = corner1.get(0,0);
            double a0 = a[0];
            double a1 = a[1];
            String sa0 = Double.toString(a0);
            String sa1 = Double.toString(a1);

            double b[] = corner1.get(0, 1);
            double b0 = b[0];
            double b1 = b[1];
            String sb0 = Double.toString(b0);
            String sb1 = Double.toString(b1);

            double c[] = corner1.get(0, 2);
            double c0 = c[0];
            double c1 = c[1];
            String sc0 = Double.toString(c0);
            String sc1 = Double.toString(c1);

            double d[] = corner1.get(0, 3);
            double d0 = d[0];
            double d1 = d[1];
            String sd0 = Double.toString(d0);
            String sd1 = Double.toString(d1);

            tv.setText(sid0 + "\n" + sa0 + ", " + sa1 + "\n" + sb0 + ", " + sb1 + "\n" + sc0 + ", " + sc1 + "\n" + sd0 + ", " + sd1 );

            Aruco.drawDetectedMarkers(src, corners, ids);

            Mat rvecs=new Mat();
            Mat tvecs=new Mat();
            Mat cameraMatrix = new Mat();
            Mat distCoeffs = new Mat();
            cameraMatrix = Mat.eye(3,3, CvType.CV_64FC1);
            distCoeffs = Mat.zeros(5,1,CvType.CV_64FC1);

            Aruco.estimatePoseSingleMarkers(corners, 0.04f, cameraMatrix, distCoeffs, rvecs, tvecs);

            for(int i=0;i<ids.toArray().length;i++){
                Aruco.drawAxis(src, cameraMatrix, distCoeffs, rvecs.row(i), tvecs.row(i), 0.02f);
            }
        }

        Bitmap bp1 = BitmapFactory.decodeFile(imagePath);
        Utils.matToBitmap(src, bp1);

        ImageView iv = this.findViewById(R.id.sample_img);
        iv.setImageBitmap(bp1);

        gray.release();
        src.release();
    }