Capture Flutter plugin

A Flutter plugin for Microblink's Capture SDK, an SDK used for auto-capturing high-quality images of identity documents in a user-friendly way.

The SDK provides you with a rectified image of the document, which ensures a high success rate in extracting document text or verifying document validity.

The user is guided to avoid glare, blurred images, bad lighting conditions, fingers over the document, or too much tilt. The SDK recognizes if a document is single-sided (e.g., a passport) or double-sided (e.g., a driving license) and prompts the user to scan the back side of the document when needed.

In the results, you can get a cropped, perspective-corrected image of the document, along with the original frame. Those can be processed by your app in any way required. The SDK is lightweight and can be easily integrated into your mobile app and blend in your design.

For maximum performance and full access to all features, it’s best to go with one of our native SDKs (for iOS and Android).

Table of contents

• Requirements
• Quickstart with the sample application
• Integration
• Plugin usage
• Platform specifics
  • Capture Settings
  • Analyzer Result
• Licensing
• Additional information

Requirements

The Capture Flutter plugin is built with Flutter v3.24.2. All of the versions and dependencies of the capture_flutter plugin can be viewed in the pubsec.yaml file.

The plugin has requirements on the native iOS & Android end, which can be viewed here:

Requirement	iOS	Android
OS/API version	iOS 13.0 and newer	API version 21 and newer
Camera quality	At least 1080p	At least 1080p

For more detailed information about the device requirements, see the native documentation here for iOS and Android.

Quickstart with the sample application

The sample application demonstrates how the Capture SDK is implemented and used and how to obtain the captured results.

To run it follow the steps:

1. Git clone the repository:

git clone https://github.com/BlinkID/capture-flutter.git

2. Position to the obtained Capture folder and run the initCaptureFlutterSample.sh script:

cd capture-flutter && ./initCaptureFlutterSample.sh

3. After the script finishes running, position to the sample folder and run the flutter run command:

cd sample && flutter run

4. Pick the platform to run the Capture SDK on.

Note: the plugin can be run directly via Xcode and Android Studio:

1. Open the Runner.xcworkspace in the path: sample/ios/Runner.xcworkspace to run the iOS sample application.
2. Open the android folder via Android Studio in the sample folder to run the Android sample application.

Integration

To add the Capture plugin to your Flutter application, simply add the following dependency in the pubsec.yaml:

dependencies:
...
  capture_flutter:

Plugin usage

1. After the dependency has been added to the project, first add the necessary imports:

import 'package:capture_flutter/capture_flutter.dart';
import 'package:capture_flutter/capture_settings.dart';
import 'package:capture_flutter/capture_enums.dart';
import 'package:capture_flutter/capture_analyzer_result.dart';

2. Initialize the Capture plugin:

final capturePlugin = CaptureFlutter();

3. Set all of the necessary Capture settings (Analyzer, UX, and Camera). You do not need to modify anything from these settings:

// Create Capture settings
final settings = CaptureSettings();

// Modify Capture UX settings
settings.uxSettings?.showOnboardingInfo = true;
settings.uxSettings?.showIntroductionDialog = true;
settings.uxSettings?.showHelpTooltipTimeIntervalMs = 2000;

// Modify Capture Analyzer settings
settings.analyzerSettings?.captureStrategy = CaptureStrategy.Default;
settings.analyzerSettings?.documentFramingMargin = 0.01;
settings.analyzerSettings?.keepMarginOnTransformedDocumentImage = true;

// Modify Capture Camera settings
settings.cameraSettings?.iosCameraResolution = IosCameraResolution.Resolution4K;

4. Add the license key and previously configured Capture settings in the scanWithCamera method of the plugin, and obtain the results after the capture process has finished:

// Add the license key
var licenseKey = "";
if (Theme.of(context).platform == TargetPlatform.iOS) {
    licenseKey = "your-iOS-license-key";
} else if (Theme.of(context).platform == TargetPlatform.android) {
    licenseKey = 'your-Android-license-key';
} else {
    licenseKey = "";
}

// Add the license key and the Capture settings in the scanWithCamera method
var results = await capturePlugin.scanWithCamera(settings,licenseKey);

if (results?.completenessStatus == CompletenessStatus.Complete) {
  // handle the obtained results
  print(results?.documentGroup);
}

• The whole integration process can be found in the sample app main.dart file here.
• The settings results that can be used with the Capture plugin can be found in the paragraphs below, but also in the comments of each result in the Dart files.

Platform specifics

Plugin implementation is located in the lib folder, while platform-specific implementation is located in the android and ios folders.

Capture Settings

With the CaptureSettings class, Capture's AnalyzerSettings, UxSettings and CameraSettings can be modified.

The capture_settings.dart file contains all the settings that can be modified and explains what each setting does.

The native implementation of the CaptureSettings can be found here:

• iOS:
  • Capture Settings
  • Analyzer Settings
  • UX Settings
  • Camera Settings
• Android:
  • Capture Settings
  • Analyzer Settings
  • UX Settings
  • Camera Settings

For a more detailed explanation of the Capture Settings, go to the native documentation here for iOS and Android.

Analyzer Result

The AnalyzerResult class represents the result of the capture process, and it is available after the scanning process finishes.

All of the results that can be obtained, along with the explanation of what each property returns, can be found in the capture_analyzer_result.dart file.

The native implementation of the AnalyzerResult can be found here:

• iOS
• Android

For a more detailed explanation of the Analyzer Result, go to the native documentation here for iOS and Android.

Licensing

A valid license key is required to initialize the Capture plugin. A free trial license key can be requested after registering at Microblink Developer Hub.

Additional information

For any additional questions and information, feel free to contact us here.