Mat teste = new Mat();
    Mat mRgba = teste.clone();
    Mat outputMat = new Mat();

    BitmapDrawable drawable = (BitmapDrawable) imageView.getDrawable();
    Bitmap bitmap = drawable.getBitmap();
    Utils.bitmapToMat(bitmap, teste);

    MatOfKeyPoint myKeyPoints = new MatOfKeyPoint();
    FeatureDetector orb = FeatureDetector.create(FeatureDetector.ORB);
    orb.detect(teste, myKeyPoints);

    List<KeyPoint> referenceKeypointsList =
            myKeyPoints.toList();


    Imgproc.cvtColor(teste, mRgba, Imgproc.COLOR_RGBA2RGB,4);
    Features2d.drawKeypoints(mRgba, myKeyPoints, mRgba, new Scalar(2,254,255), Features2d.DRAW_RICH_KEYPOINTS);
    Imgproc.cvtColor(mRgba, outputMat, Imgproc.COLOR_RGB2RGBA);
    Utils.matToBitmap(outputMat, bitmap);

    imageView.setImageBitmap(bitmap);