如何在(JavaCameraView) CameraBridgeViewBase中设置自定义亮度调整？

import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.JavaCameraView;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;

public class MainActivity extends AppCompatActivity implements CvCameraViewListener2 {
    private CameraBridgeViewBase mOpenCvCameraView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mOpenCvCameraView = (JavaCameraView) findViewById(R.id.camera_view);
        mOpenCvCameraView.setCvCameraViewListener(this);
    }

    @Override
    public void onCameraViewStarted(int width, int height) {
    }

    @Override
    public void onCameraViewStopped() {
    }

    @Override
    public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
        Mat frame = inputFrame.rgba();

        // 调整亮度
        Core.addWeighted(frame, 1.5, new Mat(frame.size(), CvType.CV_8UC4, new Scalar(50, 50, 50)), -0.5, frame);

        return frame;
    }
}