public void load() {
    // init opencv (see also mLoaderCallback below)
    OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_9, a, mLoaderCallback);
}

// callback function when OpenCVLoader.initAsync is finished
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(a) {
    @Override
    public void onManagerConnected(int status) {
        switch (status) {
            case LoaderCallbackInterface.SUCCESS:
            {
                // position 1

                // test opencvImageTransformation1()
                opencvImageTransformation1();

                // test opencvImageTransformation3()
                opencvImageTransformation3();

            } break;
            default:
            {
                super.onManagerConnected(status);
            } break;
        }
    }
};

public void opencvImageTransformation1() {
    // do something
}

public void opencvImageTransformation2() {
    // do something
}

public void opencvImageTransformation3() {
    // do something
}