Android App Crashes on using anything from OpenCV

Question

I have tried to install OpenCV for Java-App Development in Android Studio. The app starts on the emulator and tried to load but instantly shuts down. This happens when the app encounter anything related to OpenCV in the code (excluding imports).

This is not the entire project, if you want to compile and need everything drop a comment

package com.example.cse535a1;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
import android.content.Context;
import android.view.View;
import android.hardware.*;
import android.widget.FrameLayout;

import org.opencv.core.*;


public class MainActivity extends AppCompatActivity {
    Camera c;

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

        if (!(getApplicationContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA))) {
            this.finish();
            System.exit(0);
        }

//        System.loadLibrary(Core.NATIVE_LIBRARY_NAME); ---------------------------------CRASHES HERE
//        Mat mat = Mat.eye(3, 3, CvType.CV_8UC1);
//        Log.i("OPENCV", mat.dump());

        Button button_symptoms = (Button)findViewById(R.id.button_symptoms);
        Button button_upload_signs = (Button)findViewById(R.id.button_upload_signs);
        Button button_measure_heart_rate = (Button)findViewById(R.id.button_measure_heart_rate);
        Button button_measure_respiratory_rate = (Button)findViewById(R.id.button_measure_respiratory_rate);

        c = getcam();
        CameraView cv1 = new CameraView(getApplicationContext(), c);

        FrameLayout view_camera = (FrameLayout)findViewById(R.id.view_camera);
        view_camera.addView(cv1);


        button_symptoms.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg_view) {
                Intent intent = new Intent(getApplicationContext(), Loggin_symptoms.class);
                startActivity(intent);
            }
        });

        button_upload_signs.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg_view) {

            }
        });

        button_measure_heart_rate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg_view) {

            }
        });

        button_measure_respiratory_rate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg_view) {
                SensorManager manager_sensor = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
                Sensor sensor_accelerometer = manager_sensor.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
            }
        });
    }

I have previously done some research before posting on StackOverflow and I found this-> Android crashes when using OpenCV from activity

This has led me to the install instructions on-> Installing OpenCV 2.4.13.7. The necessary part can be found under Application Development with Static Initialization.

But unfortunately, the entire process of having an Android.mk file is no longer in use. So to solve this problem what do I do now?

Is there a different file where the OPENCV_INSTALL_MODULES:=on line must be inserted?

score 0 · Answer 1 · answered Feb 13 '21 at 21:52

0

So, I think I have found the solution to this problem in my case. Upon looking in the Logcat tab in Android studio, I noticed a problem that libopencv_java451.so was not found. In the jniLibs folder there was instead libopencv_java4.so.

A simple rename fixed this problem. There are two places where I renamed the files.

jniLibs folder in the project directory
jniLibs in the opencv sdk directory (though this one might be ultimately responsible)

Depending on the system (for me-> x86 and x86_64), rename your files.

I have attached a pic showing my project file structure, look at the large yellow marks which show the renamed files.

answered Feb 13 '21 at 21:52

Vishwad

251
3
18

So the moral of the story *isn't* "filename libopencv_java4.so". The key takeaway should be: `LOOK AT YOUR LOGCAT!` It should have explicitly said "failed to open libxyz" (or something to that effect). – paulsm4 Feb 13 '21 at 21:55
True. I am a grad student coding in Android Studio for the first time. Don't have enough experience of stuff. – Vishwad Feb 13 '21 at 22:05

Android App Crashes on using anything from OpenCV

1 Answers1