How to read the image data of the camera application into OpenCV

After taking a picture with a camera, we are creating an app that allows you to enter any character into the image.

I'm thinking about how to do it as follows:

Launch the camera application created by Android Studio, take pictures, and obtain image data
Read the image data into opencv and insert characters into the image.

Currently, the camera application has been completed, so I don't know how to import the image data taken in opencv from here.

Could someone please tell me?

Thank you for your cooperation.

Camera app source code

import android.app.Activity;
    import android.content.Intent;
    import android.graphics.Bitmap;
    import android.os.Bundle;
    import android.provider.MediaStore;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.ImageView;

    public class MainActivity extensions Activity {

    static final int REQUEST_CAPTURE_IMAGE=100;

    Button button 1;
    ImageView imageView1;

    @ Override
    public void onCreate (Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViews();
        setListeners();
    }

    protected void findViews() {
        button1 = (Button) findViewById (R.id.button1);
        imageView 1=(ImageView) findViewById (R.id.imageView1);
    }

    protected void setListeners() {
        button1.setOnClickListener(newOnClickListener(){
            @ Override
            public void onClick (View v) {
                Intent = new Intent(
                        MediaStore.ACTION_IMAGE_CAPTURE);
                startActivityForResult(
                        int,
                        REQUEST_CAPTURE_IMAGE);
            }
        });
    }

    @ Override
    protected void onActivityResult(
            int requestCode,
            int resultCode,
            US>Intent data) {
        if(REQUEST_CAPTURE_IMAGE==requestCode
                &resultCode==Activity.RESULT_OK){
            Bitmap capturedImage=
                    (Bitmap) data.getExtras().get("data");
            imageView 1.setImageBitmap(capturedImage);
        }
    }

}

java android opencv

2022-09-30 21:28

1 Answers

Do you have an environment to develop OpenCV on Android?
If not, download opencv from the formula and set up the library.
Create your own project if it's a simple opencv capture and put it in AndroidManifest.xml

<uses-permission android:name="android.permission.CAMERA"/>
<uses-feature android:name="android.hardware.camera2"android:required="false"/>
<uses-feature android:name="android.hardware.camera2.autofocus"android:required="false"/>

Add to layout

<org.opencv.android.JavaCameraView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:visibility="gone"
    android:id="@+id/tutorial1_activity_java_surface_view"
    opencv:show_fps="true"
    openscv:camera_id="any"/>

Add to Main

import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Mat;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;
 
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SurfaceView;
import android.view.WindowManager;
import android.widget.Toast;
 
public class MainActivity extensions AppCompatActivity implements CameraBridgeViewBase.CvCameraViewListener{
    private static final String TAG = "OCVSample::Activity";
 
    private CameraBridgeViewBase mOpenCvCameraView;
    private boolean mIsJavaCamera=true;
    private MenuItemmItemSwitchCamera=null;
 
    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;
            }
        }
    };
 
    publicMainActivity(){
        Log.i(TAG, "Instantiated new" + this.getClass());
    }
 
    /** Called when the activity is first created.*/
    @ Override
    public void onCreate (Bundle savedInstanceState) {
        Log.i(TAG, "called onCreate");
        super.onCreate(savedInstanceState);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
 
        setContentView(R.layout.activity_main);
 
        mOpenCvCameraView= (CameraBridgeViewBase) findViewById (R.id.tutorial1_activity_java_surface_view);
 
        mOpenCvCameraView.setVisibility (SurfaceView.VISIBLE);
 
        mOpenCvCameraView.setCvCameraViewListener(this);
    }
 
    @ Override
    public void onPause()
    {
        super.onPause();
        if(mOpenCvCameraView!=null)
            mOpenCvCameraView.disableView();
    }
 
    @ Override
    public void onResume()
    {
        super.onResume();
        if(!OpenCVLoader.initDebug()){
            Log.d(TAG, "Internal OpenCV library not found.Using OpenCV Manager for initialization");
            OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_0_0, this, mLoaderCallback);
        } else{
            Log.d(TAG, "OpenCV library found inside package.Using it!");
            mLoaderCallback.onManagerConnected (LoaderCallbackInterface.SUCCESS);
        }
    }
 
    public void onDestroy() {
        super.onDestroy();
        if(mOpenCvCameraView!=null)
            mOpenCvCameraView.disableView();
    }
 
    public void onCameraViewStarted(int width, int height) {
    }
 
    public void onCameraViewStopped(){
    }
 
    public MatonCameraFrame (MatinputFrame) {
        return inputFrame;
    }
}

Try to run the .
I think there will be errors in build.grable and main, but please adjust it to your environment.
By the way, my code is OpenCV 3.2.

2022-09-30 21:28

If you have any answers or tips

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