Google Vision Flutter Widget

A Flutter widget package that integrates Google Cloud Vision image labeling, face, logo, landmark, text detection, and more into your Flutter applications.

Table of Contents

• Quick Start
• Features
  • Image Detection
  • File Detection
• Configuration
  • GoogleVision Initialization
  • Builder Parameters
• Examples
• API Reference
• Contributors
• Contributing
• License

---

Quick Start

1. Add dependency

dependencies:
  google_vision_flutter: ^2.0.0+12

2. Authenticate

Obtain credentials via an API key or a service account JSON file:

Authenticating to the Cloud Vision API requires an API key or a JSON file with the JWT token information. The JWT token can be obtained by creating a service account in the Google API console.

// Using a service account JSON file from your Flutter assets
final googleVision = GoogleVision().withAsset('assets/service_credentials.json');

3. Use the builder widget

import 'package:flutter/material.dart';
import 'package:google_vision_flutter/google_vision_flutter.dart';

GoogleVisionImageBuilder.labelDetection(
  googleVision: googleVision,
  imageProvider: Image.asset('assets/photo.jpg').image,
  builder: (context, List<EntityAnnotation>? annotations) {
    return Column(
      children: annotations!
          .map((entity) => Text(
              '${(entity.score! * 100).toStringAsFixed(2)}% - ${entity.description}'))
          .toList(),
    );
  },
);

See the example app for the complete working project.

---

Features

Image Detection (GoogleVisionImageBuilder)

Analyze images via the Cloud Vision API using declarative Flutter widgets:

Feature	Builder Factory	Annotation Type
Label Detection	GoogleVisionImageBuilder.labelDetection()	EntityAnnotation
Face Detection	GoogleVisionImageBuilder.faceDetection()	FaceAnnotation
Landmark Detection	GoogleVisionImageBuilder.landmarkDetection()	EntityAnnotation
Logo Detection	GoogleVisionImageBuilder.logoDetection()	EntityAnnotation
Text Detection	GoogleVisionImageBuilder.textDetection()	EntityAnnotation
Document Text Detection	GoogleVisionImageBuilder.documentTextDetection()	FullTextAnnotation
Object Localization	GoogleVisionImageBuilder.objectLocalization()	LocalizedObjectAnnotation
Safe Search Detection	GoogleVisionImageBuilder.safeSearchDetection()	SafeSearchAnnotation
Image Properties	GoogleVisionImageBuilder.imageProperties()	ImagePropertiesAnnotation
Crop Hints	GoogleVisionImageBuilder.cropHints()	CropHintsAnnotation
Web Detection	GoogleVisionImageBuilder.webDetection()	WebDetection
Product Search	GoogleVisionImageBuilder.productSearch()	ProductSearchResults

File Detection (GoogleVisionFileBuilder)

Analyze PDF / TIFF files using the Cloud Vision API:

Feature	Builder Factory
Label Detection	GoogleVisionFileBuilder.labelDetection()
Face Detection	GoogleVisionFileBuilder.faceDetection()
Landmark Detection	GoogleVisionFileBuilder.landmarkDetection()
Logo Detection	GoogleVisionFileBuilder.logoDetection()
Text Detection	GoogleVisionFileBuilder.textDetection()
Document Text Detection	GoogleVisionFileBuilder.documentTextDetection()
Object Localization	GoogleVisionFileBuilder.objectLocalization()
Safe Search Detection	GoogleVisionFileBuilder.safeSearchDetection()
Image Properties	GoogleVisionFileBuilder.imageProperties()
Crop Hints	GoogleVisionFileBuilder.cropHints()
Web Detection	GoogleVisionFileBuilder.webDetection()
Product Search	GoogleVisionFileBuilder.productSearch()

---

Configuration

GoogleVision Initialization

Method	Description
GoogleVision().withAsset(path)	Load JWT credentials from a Flutter asset
GoogleVision().withApiKey(key)	Authenticate using an API key
GoogleVision(LogLevel.all).withAsset(path)	Enable verbose logging

Builder Parameters

Parameter	Type	Default	Description
googleVision	FutureOr<GoogleVision>	required	The Google Vision instance
imageProvider / inputConfig	varies	required	The image to analyze or file config
builder	Widget Function(...)	required	Widget builder for the results
maxResults	int	10	Maximum results per feature
onError	Widget Function(Object)?	null	Custom error widget
onLoading	Widget Function()?	null	Custom loading widget
parent	String?	null	Target project/location (e.g. projects/my-project/locations/us)

---

Examples

Explore the example app for full usage of all detection features.

---

API Reference

This package re-exports the google_vision Dart package (hiding Color, GoogleVision, JsonImage, and InputConfig which have Flutter-specific replacements).

For detailed API documentation, see:

• Google Vision Dart package
• Example app source

---

Contributors

• hieupm2096

Contributing

Any help from the open-source community is always welcome and needed:

• Found an issue? Please fill a bug report with details.
• Need a feature? Open a feature request with use cases.
• Are you using and liking the project? Promote the project or make a donation.
• Are you a developer? Fix a bug and send a pull request.

License

MIT