This post describes how to extract text from images using MLKIT.
In app level build.gradle add the mlkit dependency.
plugins {
id 'com.android.application'
}
android {
compileSdkVersion 30
buildToolsVersion "30.0.3"
defaultConfig {
applicationId "com.example.pickfile"
minSdkVersion 21
targetSdkVersion 30
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:1.3.1'
implementation 'com.google.android.material:material:1.4.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.1'
implementation 'com.google.android.gms:play-services-mlkit-text-recognition:17.0.0'
testImplementation 'junit:junit:4.+'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}In AndroidManifest.xml add metadata for MLKIT.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.pickfile">
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:usesCleartextTraffic="true"
android:theme="@style/Theme.PickFile">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".ResultActivity"
android:hardwareAccelerated="true"/>
<meta-data
android:name="com.google.mlkit.vision.DEPENDENCIES"
android:value="ocr" />
</application>
</manifest>Create your layout in activity_main.xml.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="PICK FILE"
android:textSize="20sp"
app:layout_constraintEnd_toStartOf="@id/button2"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="@+id/imageView"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/button1"
tools:srcCompat="@tools:sample/avatars" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Extract text"
android:layout_margin="10dp"
android:textSize="20sp"
app:layout_constraintStart_toEndOf="@id/button1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>In MainActivity.java use following codes.
package com.example.pickfile;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import androidx.activity.result.ActivityResultCallback;
import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
ImageView imageview1;
String uriString = "";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button1 = findViewById(R.id.button1);
Button button2 = findViewById(R.id.button2);
imageview1 = findViewById(R.id.imageView);
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mGetContent.launch("image/*");
}
});
button2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, ResultActivity.class);
intent.putExtra("uri", uriString);
startActivity(intent);
}
});
}
ActivityResultLauncher<String> mGetContent = registerForActivityResult(
new ActivityResultContracts.GetContent(),
new ActivityResultCallback<Uri>() {
@Override
public void onActivityResult(Uri uri) {
imageview1.setImageURI(uri);
uriString = uri.toString();
}
});
}Add a layout file result.xml with an EditText.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<EditText
android:id="@+id/edittext1"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_margin="10dp"
android:gravity="start"
android:hint="EditText"
android:textSize="20sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>In ResultActivity.java use following codes.
package com.example.pickfile;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.widget.EditText;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;
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.io.IOException;
public class ResultActivity extends AppCompatActivity {
EditText edittext1;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.result);
edittext1 = findViewById(R.id.edittext1);
String uriString = getIntent().getStringExtra("uri");
Uri uri = Uri.parse(uriString);
_extractTextFromUri(getApplicationContext(), uri);
}
public void _extractTextFromUri(Context context, Uri _uri) {
TextRecognizer recognizer = TextRecognition.getClient(TextRecognizerOptions.DEFAULT_OPTIONS);
try {
InputImage image = InputImage.fromFilePath(context, _uri);
Task<Text> result =
recognizer.process(image)
.addOnSuccessListener(new OnSuccessListener<Text>() {
@Override
public void onSuccess(Text visionText) {
// Task completed successfully
edittext1.setText(visionText.getText());
}
})
.addOnFailureListener(
new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
// Task failed with an exception
}
});
} catch (IOException e) {
e.printStackTrace();
}
}
}
Now run the app.