packages/firebase_ml_vision/README.md

# ML Kit Vision for Firebase

[![pub package](https://img.shields.io/pub/v/firebase_ml_vision.svg)](https://pub.dartlang.org/packages/firebase_ml_vision)

A Flutter plugin to use the [ML Kit Vision for Firebase API](https://firebase.google.com/docs/ml-kit/).

For Flutter plugins for other Firebase products, see [FlutterFire.md](https://github.com/flutter/plugins/blob/master/FlutterFire.md).

*Note*: This plugin is still under development, and some APIs might not be available yet. [Feedback](https://github.com/flutter/flutter/issues) and [Pull Requests](https://github.com/flutter/plugins/pulls) are most welcome!

## Usage

To use this plugin, add `firebase_ml_vision` as a [dependency in your pubspec.yaml file](https://flutter.io/platform-plugins/). You must also configure Firebase for each platform project: Android and iOS (see the example folder or https://codelabs.developers.google.com/codelabs/flutter-firebase/#4 for step by step details).

### Android
If you're using the on-device `ImageLabeler`, include the latest matching [ML Kit: Image Labeling](https://firebase.google.com/support/release-notes/android) dependency in your app-level build.gradle file.

```xml
android {
    dependencies {
        // ...

        api 'com.google.firebase:firebase-ml-vision-image-label-model:17.0.2'
    }
}
```

If you're using the on-device `Face Contour Detection`, include the latest matching [ML Kit: Face Detection Model](https://firebase.google.com/support/release-notes/android) dependency in your app-level build.gradle file.

```
android {
    dependencies {
        // ...

        api 'com.google.firebase:firebase-ml-vision-face-model:17.0.2'
    }
}
```

If you receive compilation errors, try an earlier version of [ML Kit: Image Labeling](https://firebase.google.com/support/release-notes/android).

Optional but recommended: If you use the on-device API, configure your app to automatically download the ML model to the device after your app is installed from the Play Store. To do so, add the following declaration to your app's AndroidManifest.xml file:

```xml
<application ...>
  ...
  <meta-data
    android:name="com.google.firebase.ml.vision.DEPENDENCIES"
    android:value="ocr" />
  <!-- To use multiple models: android:value="ocr,label,barcode,face" -->
</application>
```

### iOS
Versions `0.7.0+` use the latest ML Kit for Firebase version which requires a minimum deployment
target of 9.0. You can add the line `platform :ios, '9.0'` in your iOS project `Podfile`.

If you're using one of the on-device APIs, include the corresponding ML Kit library model in your
`Podfile`. Then run `pod update` in a terminal within the same directory as your `Podfile`.

```
pod 'Firebase/MLVisionBarcodeModel'
pod 'Firebase/MLVisionFaceModel'
pod 'Firebase/MLVisionLabelModel'
pod 'Firebase/MLVisionTextModel'
```

## Using an ML Vision Detector

### 1. Create a `FirebaseVisionImage`.

Create a `FirebaseVisionImage` object from your image. To create a `FirebaseVisionImage` from an image `File` object:

```dart
final File imageFile = getImageFile();
final FirebaseVisionImage visionImage = FirebaseVisionImage.fromFile(imageFile);
```

### 2. Create an instance of a detector.

Get an instance of a `FirebaseVisionDetector`.

```dart
final BarcodeDetector barcodeDetector = FirebaseVision.instance.barcodeDetector();
final ImageLabeler cloudLabeler = FirebaseVision.instance.cloudImageLabeler();
final FaceDetector faceDetector = FirebaseVision.instance.faceDetector();
final ImageLabeler labeler = FirebaseVision.instance.imageLabeler();
final TextRecognizer textRecognizer = FirebaseVision.instance.textRecognizer();
```

You can also configure all detectors, except `TextRecognizer`, with desired options.

```dart
final ImageLabeler labeler = FirebaseVision.instance.imageLabler(
  ImageLabelerOptions(confidenceThreshold: 0.75),
);
```

### 3. Call `detectInImage()` or `processImage()` with `visionImage`.

```dart
final List<Barcode> barcodes = await barcodeDetector.detectInImage(visionImage);
final List<ImageLabel> cloudLabels = await cloudLabeler.processImage(visionImage);
final List<Face> faces = await faceDetector.processImage(visionImage);
final List<ImageLabel> labels = await labeler.processImage(visionImage);
final VisionText visionText = await textRecognizer.processImage(visionImage);
```

### 4. Extract data.

a. Extract barcodes.

```dart
for (Barcode barcode in barcodes) {
  final Rectangle<int> boundingBox = barcode.boundingBox;
  final List<Point<int>> cornerPoints = barcode.cornerPoints;

  final String rawValue = barcode.rawValue;

  final BarcodeValueType valueType = barcode.valueType;

  // See API reference for complete list of supported types
  switch (valueType) {
    case BarcodeValueType.wifi:
      final String ssid = barcode.wifi.ssid;
      final String password = barcode.wifi.password;
      final BarcodeWiFiEncryptionType type = barcode.wifi.encryptionType;
      break;
    case BarcodeValueType.url:
      final String title = barcode.url.title;
      final String url = barcode.url.url;
      break;
  }
}
```

b. Extract faces.

```dart
for (Face face in faces) {
  final Rectangle<int> boundingBox = face.boundingBox;

  final double rotY = face.headEulerAngleY; // Head is rotated to the right rotY degrees
  final double rotZ = face.headEulerAngleZ; // Head is tilted sideways rotZ degrees

  // If landmark detection was enabled with FaceDetectorOptions (mouth, ears,
  // eyes, cheeks, and nose available):
  final FaceLandmark leftEar = face.getLandmark(FaceLandmarkType.leftEar);
  if (leftEar != null) {
    final Point<double> leftEarPos = leftEar.position;
  }

  // If classification was enabled with FaceDetectorOptions:
  if (face.smilingProbability != null) {
    final double smileProb = face.smilingProbability;
  }

  // If face tracking was enabled with FaceDetectorOptions:
  if (face.trackingId != null) {
    final int id = face.trackingId;
  }
}
```

c. Extract labels.

```dart
for (ImageLabel label in labels) {
  final String text = label.text;
  final String entityId = label.entityId;
  final double confidence = label.confidence;
}
```

d. Extract text.

```dart
String text = visionText.text;
for (TextBlock block in visionText.blocks) {
  final Rect boundingBox = block.boundingBox;
  final List<Offset> cornerPoints = block.cornerPoints;
  final String text = block.text;
  final List<RecognizedLanguage> languages = block.recognizedLanguages;

  for (TextLine line in block.lines) {
    // Same getters as TextBlock
    for (TextElement element in line.elements) {
      // Same getters as TextBlock
    }
  }
}
```

### 5. Release resources with `close()`.

```dart
barcodeDetector.close();
cloudLabeler.close();
faceDetector.close();
labeler.close();
textRecognizer.close();
```

## Getting Started

See the `example` directory for a complete sample app using ML Kit Vision for Firebase.