OCR-mlkit-01.java

-----------------------------activity_main.xml



<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/imageId"
        android:layout_width="match_parent"
        android:layout_height="372dp" />
    <Button
        android:id="@+id/buttonId"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="take pic"/>
        <!-- android:onClick="doProcess" -->

    <TextView
        android:id="@+id/textId"
        android:layout_width="match_parent"
        android:layout_height="221dp" />

</LinearLayout>



-----------------------------AndroidManifest.xml



<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.mlkit02">

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.CAMERA"/>
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Mlkit02"
        android:requestLegacyExternalStorage="true"
        tools:targetApi="29">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>



-----------------------------build.gradle



plugins {
    id 'com.android.application'
}

android {
    compileSdk 32

    defaultConfig {
        applicationId "com.example.mlkit02"
        minSdk 23
        targetSdk 32
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

dependencies {

    implementation 'androidx.appcompat:appcompat:1.4.2'
    implementation 'com.google.android.material:material:1.6.1'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
    implementation 'com.google.android.gms:play-services-mlkit-text-recognition:18.0.0'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}


-----------------------------MainActivity.java


package com.example.mlkit02;

import androidx.activity.result.ActivityResult;
import androidx.activity.result.ActivityResultCallback;
import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Camera;
import android.os.Build;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;
import com.google.android.gms.tasks.Tasks;
import com.google.mlkit.vision.common.InputImage;
import com.google.mlkit.vision.text.Text;
import com.google.mlkit.vision.text.TextRecognition;
import com.google.mlkit.vision.text.TextRecognizer;
import com.google.mlkit.vision.text.latin.TextRecognizerOptions;

import java.util.concurrent.ExecutionException;

public class MainActivity extends AppCompatActivity {

    ImageView imageView;
    TextView textView;
    Button pictButton;

    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageView = findViewById(R.id.imageId);
        textView = findViewById(R.id.textId);
        pictButton = findViewById(R.id.buttonId);

        if (checkSelfPermission(Manifest.permission.ACCESS_NETWORK_STATE) == PackageManager.PERMISSION_DENIED ||
                checkSelfPermission(Manifest.permission.CAMERA) == PackageManager.PERMISSION_DENIED ||
                checkSelfPermission(Manifest.permission.INTERNET) == PackageManager.PERMISSION_DENIED ||
                checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED ||
                checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED) {
            //permission not enabled, request it
            String[] permission = {Manifest.permission.ACCESS_NETWORK_STATE, Manifest.permission.INTERNET, Manifest.permission.CAMERA, Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE};
            requestPermissions(permission, 1000);
        }

        pictButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //Camera camera = getAndroidCamera();

                Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                someActivityResultLauncher.launch(cameraIntent);
            }
        });
    }

    ActivityResultLauncher<Intent> someActivityResultLauncher = registerForActivityResult(
            new ActivityResultContracts.StartActivityForResult(),
            new ActivityResultCallback<ActivityResult>() {
                @Override
                public void onActivityResult(ActivityResult result) {
                    if (result.getResultCode() == Activity.RESULT_OK) {
                        Intent data = result.getData();
                        Bundle bundle = data.getExtras();
                        Bitmap bitmap = (Bitmap) bundle.get("data");
                        imageView.setImageBitmap(bitmap);

                        String output = null;
                        try {
                            output = new OCR(imageView).execute().get(); //"/storage/emulated/0/Download/sticker01.jpg"
                        } catch (ExecutionException e) {
                            e.printStackTrace();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        Log.i("===============OCR==RESULT======================>", output);
                        textView.setText(output);
                    }
                }
    });
}



-----------------------------OCR.java



package com.example.mlkit02;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.os.AsyncTask;
import android.os.SystemClock;
import android.util.Log;
import android.widget.ImageView;

import androidx.annotation.NonNull;

import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;
import com.google.android.gms.tasks.Tasks;
import com.google.mlkit.vision.common.InputImage;
import com.google.mlkit.vision.text.Text;
import com.google.mlkit.vision.text.TextRecognition;
import com.google.mlkit.vision.text.TextRecognizer;
import com.google.mlkit.vision.text.latin.TextRecognizerOptions;

import java.lang.ref.WeakReference;

public class OCR  extends AsyncTask<String, Void, String> {

    private ImageView mImgView;
    public OCR(ImageView image) {
        //WeakReference<ImageView> mImageView = new WeakReference<ImageView>(image);
        mImgView = image;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        String resultText = null;
        try {
            //ImageView imgView = (ImageView) findViewById(R.id.params[0]);
            BitmapDrawable drawable = (BitmapDrawable) mImgView.getDrawable();
            Bitmap bitmap = drawable.getBitmap();
            //Bitmap bitmap = BitmapFactory.decodeFile(params[0]);//"/storage/emulated/0/Download/wp01.png" //"/storage/emulated/0/DCIM/Camera/1659023147826.jpg"

            TextRecognizer recognizer = TextRecognition.getClient(TextRecognizerOptions.DEFAULT_OPTIONS);
            InputImage mInputImage = InputImage.fromBitmap(bitmap, 0);

            Task<Text> result =
                    recognizer.process(mInputImage).addOnSuccessListener(new OnSuccessListener<Text>() {
                                //@Override
                                public void onSuccess(Text visionText) {

                                }
                            })
                            .addOnFailureListener(
                                    new OnFailureListener() {
                                        @Override
                                        public void onFailure(@NonNull Exception e) {

                                        }
                                    });
            Tasks.await(result);

            resultText = result.getResult().getText();
            //Log.i("RESULT ======================>", resultText);
        } catch (Exception e) {
            e.printStackTrace();
            Log.e("Task failed", e.getMessage());
        }

        return resultText;
    }

    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);
    }
}