No implementation found for long org.opencv.aruco.Aruco.getPredefinedDictionary

[Yogeshvasu]

hello i am trying to detect the aruco marker but i am getting error No implementation found for long org.opencv.aruco.Aruco.getPredefinedDictionary based on my code

package com.example.opencv_aruco;

import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.WindowManager; import android.widget.Button; import android.widget.Toast;

import org.opencv.android.BaseLoaderCallback; import org.opencv.android.CameraBridgeViewBase; import org.opencv.android.LoaderCallbackInterface; import org.opencv.android.OpenCVLoader; import org.opencv.aruco.Aruco; import org.opencv.aruco.Dictionary; import org.opencv.core.Mat; import org.opencv.core.MatOfInt; import org.opencv.core.Scalar; import org.opencv.imgproc.Imgproc;

import java.util.ArrayList; import java.util.List;

public class MainActivity extends Activity implements CameraBridgeViewBase.CvCameraViewListener2 {

private static final String TAG = "MainActivity";
private CameraBridgeViewBase mOpenCvCameraView;
private Dictionary mDictionary;
private MatOfInt mIds;
private List<Mat> mCorners;
private boolean isDetecting = false;
private Button btnDetectMarker;

private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
    @Override
    public void onManagerConnected(int status) {
        switch (status) {
            case LoaderCallbackInterface.SUCCESS:
                Log.i(TAG, "OpenCV loaded successfully");
                mOpenCvCameraView.enableView();
                break;
            default:
                super.onManagerConnected(status);
                break;
        }
    }
};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
    setContentView(R.layout.activity_main);

    mOpenCvCameraView = findViewById(R.id.camera_view);
    mOpenCvCameraView.setVisibility(CameraBridgeViewBase.VISIBLE);
    mOpenCvCameraView.setCvCameraViewListener(this);

    btnDetectMarker = findViewById(R.id.btn_detect_marker);
    btnDetectMarker.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            isDetecting = true;
        }
    });

    mDictionary = Aruco.getPredefinedDictionary(Aruco.DICT_5X5_50);
    mIds = new MatOfInt();
    mCorners = new ArrayList<>();
}

@Override
protected void onResume() {
    super.onResume();
    if (OpenCVLoader.initDebug()) {
        Log.d(TAG, "OpenCV initialization succeeded");
        mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
    } else {
        Log.d(TAG, "OpenCV initialization failed");
        Toast.makeText(this, "OpenCV initialization failed", Toast.LENGTH_LONG).show();
    }
}

@Override
protected void onPause() {
    super.onPause();
    if (mOpenCvCameraView != null)
        mOpenCvCameraView.disableView();
}

@Override
protected void onDestroy() {
    super.onDestroy();
    if (mOpenCvCameraView != null)
        mOpenCvCameraView.disableView();
}

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

@Override
public void onCameraViewStopped() {
}

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

    if (isDetecting) {
        Mat gray = inputFrame.gray();
        mIds = new MatOfInt();
        mCorners.clear();

        // Detect markers
        Aruco.detectMarkers(gray, mDictionary, mCorners, mIds);

        // Draw markers and measure width and height
        if (mIds.total() > 0) {
            Aruco.drawDetectedMarkers(frame, mCorners, mIds, new Scalar(255, 0, 0));
            for (Mat corners : mCorners) {
                if (corners.rows() == 1 && corners.cols() == 4) {
                    for (int i = 0; i < 4; i++) {
                        Imgproc.line(frame,
                                new org.opencv.core.Point(corners.get(0, i)),
                                new org.opencv.core.Point(corners.get(0, (i + 1) % 4)),
                                new Scalar(0, 255, 0), 2);
                    }
                    double width = Math.sqrt(Math.pow(corners.get(0, 0)[0] - corners.get(0, 1)[0], 2) +
                            Math.pow(corners.get(0, 0)[1] - corners.get(0, 1)[1], 2));
                    double height = Math.sqrt(Math.pow(corners.get(0, 1)[0] - corners.get(0, 2)[0], 2) +
                            Math.pow(corners.get(0, 1)[1] - corners.get(0, 2)[1], 2));
                    Log.d(TAG, "Width: " + width + ", Height: " + height);
                }
            }
        }

        // Reset the flag
        isDetecting = false;
    }

    return frame;
}

}