Google Vision Images Flutter Widget

Native Dart package that integrates Google Vision features, including image labeling, face, logo, and landmark detection into Flutter applications.

Please feel free to submit PRs for any additional helper methods, or report an issue for a missing helper method and I'll add it if I have time available.

Table of Contents

• Google Vision Images Flutter Widget
  • Table of Contents
  • Getting Started
    • pubspec.yaml
    • Obtaining Authorization Credentials
    • Usage of the GoogleVisionBuilder Widget
  • Contributing

Getting Started

pubspec.yaml

To use this package, add the dependency to your pubspec.yaml file:

dependencies:
  ...
  google_vision_flutter: ^1.1.0

Obtaining Authorization Credentials

Authenticating to the Cloud Vision API requires a JSON file with the JWT token information, which you can obtain by creating a service account in the API console.

Usage of the GoogleVisionBuilder Widget

See the example app for the full code.

import 'package:flutter/material.dart';
import 'package:google_vision/google_vision.dart' as gv;
import 'package:google_vision_flutter/google_vision_flutter.dart';

class FaceDetection extends StatefulWidget {
  const FaceDetection({super.key, required this.title});

  final String title;

  @override
  State<FaceDetection> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<FaceDetection> {
  final _processImage = Image.asset(
    'assets/young-man-smiling.jpg',
    fit: BoxFit.fitWidth,
  );

  @override
  Widget build(BuildContext context) => SafeArea(
        child: Scaffold(
          appBar: AppBar(
            leading: IconButton(
              icon: const Icon(Icons.arrow_back, color: Colors.black),
              onPressed: () => Navigator.of(context).pop(),
            ),
            title: Text(widget.title),
          ),
          body: SingleChildScrollView(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                const Padding(
                  padding: EdgeInsets.all(8.0),
                  child: Text('assets/young-man-smiling.jpg'),
                ),
                Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: _processImage,
                ),
                const Padding(
                  padding: EdgeInsets.all(8.0),
                  child: Text(
                    'Processed image will appear below:',
                  ),
                ),
                Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: GoogleVisionBuilder.faceDetection(
                    googleVision: GoogleVision.withAsset(
                        'assets/service_credentials.json'),
                    imageProvider: _processImage.image,
                    builder: (BuildContext context,
                            List<gv.FaceAnnotation>? faceAnnotations,
                            ImageDetail imageDetail) =>
                        CustomPaint(
                      foregroundPainter: AnnotationPainter(
                        faceAnnotations: faceAnnotations,
                        imageDetail: imageDetail,
                      ),
                      child: Image(image: _processImage.image),
                    ),
                  ),
                )
              ],
            ),
          ),
        ),
      );
}

/// See the example project for all the necessary code.

Major Changes for v1.1.x

Starting with this version of the package, the google_vision package is not re-exported by google_vision_flutter, this means that you must import google_vision manually in the cases that you need any classes that are part of it's API.

import 'package:flutter/material.dart';
import 'package:google_vision/google_vision.dart' as gv;
import 'package:google_vision_flutter/google_vision_flutter.dart';

GoogleVisionBuilder.faceDetection(
                    googleVision: GoogleVision.withAsset(
                        'assets/service_credentials.json'),
                    imageProvider: _processImage.image,
                    builder: (BuildContext context,
                            List<gv.FaceAnnotation>? faceAnnotations,
                            ImageDetail imageDetail) =>
                        CustomPaint(
                      foregroundPainter: AnnotationPainter(
                        faceAnnotations: faceAnnotations,
                        imageDetail: imageDetail,
                      ),
                      child: Image(image: _processImage.image),
                    ),
                  ),

In this code snippet the FaceAnnotation class is referenced as gv.FaceAnnotation since the class is part of the google_vision package.

Previous versions of the google_vision_flutter package reexported the google_vision package as part of the it's library definition. This lead to warnings like:

warning: private API of package:google_Vision is reexported by libraries in other packages:

During analysis of the package. The updated package does not generate these warnings.

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: create an article or post about it
  • Make a donation
• Do you have a project that uses this package
  • let's cross promote, let me know and I'll add a link to your project
• Are you a developer?
  • Fix a bug and send a pull request.
  • Implement a new feature.
  • Improve the Unit Tests.
• Have you already helped in any way?
  • Many thanks from me, the contributors and everybody that uses this project!

If you donate 1 hour of your time, you can contribute a lot, because others will do the same, just be part and start with your 1 hour.