public class MyGdxGame extends ApplicationAdapter {
    SpriteBatch batch;
    Sprite backg;
    Sprite board;
    OrthographicCamera camera;
    Viewport viewport;
    Viewport viewportBg;
    private final Texture bgt;

    @Override
    public void create () {
        batch = new SpriteBatch();

        bgt = new Texture(Gdx.files.internal("tmp/bg.png"));
        bgt.setWrap(Texture.TextureWrap.Repeat, Texture.TextureWrap.Repeat);

        board = new Sprite(new Texture(Gdx.files.internal("tmp/br.png")));
        board.setPosition(100, 100);
        board.setSize(200, 200);

        camera = new OrthographicCamera();
        viewportBg = new ScreenViewport(camera);

//        viewport = new StretchViewport(Gdx.graphics.getWidth(), Gdx.graphics.getHeight(), camera);
        viewport = new ExtendViewport(Gdx.graphics.getWidth(), Gdx.graphics.getHeight(), camera);
    }

    @Override
    public void render(float dt) {
        camera.update();

        Gdx.gl.glClearColor(1, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        batch.begin();

        viewportBg.apply(true);
        batch.setProjectionMatrix(camera.combined);
        batch.draw(bgt, 0, 0, 0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());

        viewport.apply(true);
        batch.setProjectionMatrix(camera.combined);
        board.draw(batch);

        batch.end();
    }

    @Override
    public void dispose() {
        batch.dispose();
    }

    @Override
    public void resize(int width, int height) {
        viewport.update(width, height);
        viewportBg.update(width, height);
        camera.position.set(width / 2, height / 2, 0);
    }
}