OpenCV 4.5.0 empty JavaCameraView and JavaCamera2View

Question

I am using OpenCV version 4.5.0 latest currently to get the camera frames and process them. But the issue is after doing everything my JavaCameraView is empty blank with nothing in it. Same with JavaCamera2View. I have previously used openCV 3.4.5 same code working fine. Also till 4.1.0, after that from 4.1.1 till now issue is the same tried many things but no luck. I have also tried this solution but no luck with 4.5.0. I at least need 4.4.0 in my application cause I will be using YOLO 4 with CV. I am just using basic code just to get the frame in view. I am not getting any kind of error message in my app. Here are the codes.

MainActivity.java

package com.learn.ocv450;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.SurfaceView;
import android.widget.Toast;

import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.JavaCamera2View;
import org.opencv.android.JavaCameraView;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;

public class MainActivity extends AppCompatActivity implements CameraBridgeViewBase.CvCameraViewListener2 {

    CameraBridgeViewBase cameraBridgeViewBase;
    BaseLoaderCallback baseLoaderCallback;
    int counter = 0;

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

        cameraBridgeViewBase = (JavaCamera2View) findViewById(R.id.CameraView);
        cameraBridgeViewBase.setVisibility(SurfaceView.VISIBLE);
        cameraBridgeViewBase.setCvCameraViewListener(this);

        baseLoaderCallback = new BaseLoaderCallback(this) {
            @Override
            public void onManagerConnected(int status) {
                super.onManagerConnected(status);

                if (status == BaseLoaderCallback.SUCCESS) {
                    //OpenCVLoader.initDebug();
                    //System.loadLibrary("opencv_java4");
                    cameraBridgeViewBase.enableView();
                } else {
                    super.onManagerConnected(status);
                }
            }
        };
    }


    @Override
    protected void onResume() {
        super.onResume();

        if (!OpenCVLoader.initDebug()) {
            Toast.makeText(this, "There is problem", Toast.LENGTH_SHORT).show();
        } else {
            baseLoaderCallback.onManagerConnected(baseLoaderCallback.SUCCESS);
        }

    }

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

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (cameraBridgeViewBase != null){
            cameraBridgeViewBase.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 (counter % 2 == 0){
            Core.flip(frame, frame, 1);
            Imgproc.cvtColor(frame, frame, Imgproc.COLOR_RGBA2GRAY);
        }
        counter++;

        Toast.makeText(this, "Getting Camera Frame", Toast.LENGTH_SHORT).show();

        return frame;
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <org.opencv.android.JavaCamera2View
        android:id="@+id/CameraView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentStart="true"
        android:layout_gravity="start"
        android:visibility="visible">

    </org.opencv.android.JavaCamera2View>

</RelativeLayout>

Manifest Permissions

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" android:required="false"/>
    <uses-feature android:name="android.hardware.camera.autofocus" android:required="false"/>
    <uses-feature android:name="android.hardware.camera.front" android:required="false"/>
    <uses-feature android:name="android.hardware.camera.front.autofocus" android:required="false"/>

btw I have followed the basic drill and imported the module correctly and added it as a dependency. Also, I am getting a success message on calling OpenCVLoader.initDebug(); so openCV is installed correctly.

As a guess, opencv 4.5.0 can use camera2 api, so you need to add to manifest: — Hihikomori, Dec 18 '20 at 19:16

score 4 · Accepted Answer · answered Feb 15 '21 at 14:08

4

In OpenCV 4.1.1 and later, you need to explicitly tell OpenCV that the app has camera permissions. Try to insert "cameraBridgeViewBase.setCameraPermissionGranted();" before "cameraBridgeViewBase.enableView();" , assuming the app already has camera permissions?

answered Feb 15 '21 at 14:08

Tommy

56
2

Welcome Tommy. Please don't phrase answers as questions, others should be able to read your answer and understand a solution without having to read the comments. Be explicit in what must be done. – Daniel Maclean Feb 15 '21 at 15:42
Already, solved. But thanks for answering. – lazydevpro Feb 22 '21 at 11:54
@liva Glad you got it solved. Do you mind posting the resolution, please, so that others can benefit from your knowledge? – Buddhisthead Jun 14 '21 at 16:43
The answer above is the right answer that's why I accepted it not just upvote. @Buddhisthead – lazydevpro Jun 15 '21 at 18:13

OpenCV 4.5.0 empty JavaCameraView and JavaCamera2View

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