google_vision 1.0.5+6

Allows you to add Google Visions image labeling, face, logo, and landmark detection, OCR, and detection of explicit content, into applications.

Google Vision images REST API Client

Native Dart package that integrates Google Vision features, including image labeling, face, logo, and landmark detection, optical character recognition (OCR), and detection of explicit content, into applications.

• Cloud Vision API - Documentation Reference

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

• Table of Contents
• New for v1.0.3
• Getting Started
  • pubspec.yaml
  • Obtaining Authorization Credentials
  • Usage of the Cloud Vision API
• vision cli (google_vision at the command prompt)

New for v1.0.3

The package now includes Product Search functionality. But be warned, it is completely experimental, there has been little to no testing done.

Getting Started

pubspec.yaml

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

dependencies:
  ...
  google_vision: ^1.0.5+6

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 Cloud Vision API

  final googleVision =
      await GoogleVision.withJwt('my_jwt_credentials.json');

  final image =
      Image.fromFilePath('example/young-man-smiling-and-thumbs-up.jpg');

  // cropping an image can save time uploading the image to Google
  final cropped = image.copyCrop(70, 30, 640, 480);

  // to see the cropped image
  await cropped.writeAsJpeg('example/cropped.jpg');

  final requests = AnnotationRequests(requests: [
    AnnotationRequest(image: cropped, features: [
      Feature(maxResults: 10, type: 'FACE_DETECTION'),
      Feature(maxResults: 10, type: 'OBJECT_LOCALIZATION')
    ])
  ]);

  final annotatedResponses =
      await googleVision.annotate(requests: requests);

  for (var annotatedResponse in annotatedResponses.responses) {
    for (var faceAnnotation in annotatedResponse.faceAnnotations) {
      GoogleVision.drawText(
          cropped,
          faceAnnotation.boundingPoly.vertices.first.x + 2,
          faceAnnotation.boundingPoly.vertices.first.y + 2,
          'Face - ${faceAnnotation.detectionConfidence}');

      GoogleVision.drawAnnotations(
          cropped, faceAnnotation.boundingPoly.vertices);
    }
  }

  for (var annotatedResponse in annotatedResponses.responses) {
    //look only for Person annotations
    annotatedResponse.localizedObjectAnnotations
        .where((localizedObjectAnnotation) =>
            localizedObjectAnnotation.name == 'Person')
        .toList()
        .forEach((localizedObjectAnnotation) {
      GoogleVision.drawText(
          cropped,
          (localizedObjectAnnotation.boundingPoly.normalizedVertices.first.x *
                  cropped.width)
              .toInt(),
          (localizedObjectAnnotation.boundingPoly.normalizedVertices.first.y *
                      cropped.height)
                  .toInt() -
              16,
          'Person - ${localizedObjectAnnotation.score}');

      GoogleVision.drawAnnotationsNormalized(
          cropped, localizedObjectAnnotation.boundingPoly.normalizedVertices);
    });
  }

// output the results as a new image file
await cropped.writeAsJpeg('resulting_image.jpg');

vision cli (google_vision at the command prompt)

This package included a cli utility that can be used to return data for any API call currently supported by the package. If you want to get started quickly with the cli utility run these commands in a terminal session:

Install using dart pub:

dart pub global activate google_vision

Install using brew:

brew tap faithoflifedev/google_vision
brew install vision

Run the following command to see help:

vision --help

Result,

A command line interface for making API requests to the Google Vision.

Usage: vision <command> [arguments]

Global options:
-h, --help                                       Print this usage information.
    --credential-file=<credentials file path>    (defaults to "/Users/chris/.vision/credentials.json")

Available commands:
  detect      Run image detection and annotation for an images.
  highlight   Draw a box to highlight any objects detected.
  score       For OBJECT_LOCALIZATION, get the score(s) for the object specified with "look-for".

Please see the cli documentation README.md for more detailed usage information.