what is the of drawing contours and creating a bounding rectangle on this image, as a newbee to android and openCV. so far : What i have so far,         

 Mat imageMat = new Mat();
        
        Utils.bitmapToMat(photo, imageMat);
        Imgproc.cvtColor(imageMat, imageMat, Imgproc.COLOR_BGR2GRAY);
           Imgproc.adaptiveThreshold(imageMat, imageMat, 255,
               Imgproc.ADAPTIVE_THRESH_MEAN_C, Imgproc.THRESH_BINARY_INV, 7, 7);
        List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
        Mat hierarchy = new Mat();
        Imgproc.findContours(imageMat, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

  
        Bitmap resultBitmap = Bitmap.createBitmap(imageMat.cols(), imageMat.rows(), Bitmap.Config.ARGB_8888);
        Utils.matToBitmap(imageMat, resultBitmap);
        ((ImageView) findViewById(R.id.imageView)).setImageBitmap(resultBitmap);

[Binary image][1]


  [1]: https://i.stack.imgur.com/vNqYV.jpg