Mobile Scanner: A Universal Solution for Image Recognition

Mobile Scanner is a powerful Flutter package that leverages MLKit to perform image recognition tasks across multiple platforms, including Android, iOS, macOS, and the web. It provides an intuitive API for scanning barcodes and includes advanced features like gallery analysis and custom scan windows.

Features Supported

Mobile Scanner offers a range of capabilities:

Feature Android iOS macOS Web
| Image Analysis (Gallery)  | Yes  | Yes  | No  | No
| Return Image  | Yes  | Yes  | No  | No
| Custom Scan Window  | Yes  | Yes  | Yes  | No

Platform-Specific Setup

For Android, you can choose between the bundled or unbundled version of MLKit for barcode scanning. The bundled version increases app size by 3-10 MB, while the unbundled version requires a smaller initial footprint but downloads the necessary files on first use.

On iOS, remember to add the necessary keys to your Info.plist file:

NSCameraUsageDescription - Describe why your app needs camera access
NSPhotoLibraryUsageDescription - Describe why your app needs photo library access (for gallery features)

For macOS, ensure you have camera permission granted in Xcode's Signing & Capabilities.

Usage

1. Create a MobileScannerController:

final controller = MobileScannerController(options);

1. Handle Lifecycle Events:

class MyState extends State with WidgetsBindingObserver {
  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    switch (state) {
      case AppLifecycleState.inactive:
        controller.stop();
        _subscription.cancel();
        break;
      case AppLifecycleState.resumed:
        controller.start();
        _subscription = controller.barcodes.listen(_handleBarcode);
        break;
    }
  }
}

1. Implement a Barcode Event Handler:

void _handleBarcode(Barcode barcode) {
  // Handle barcode data
}

1. Start the Scanner:

await controller.start();

1. Display the Camera Preview:

MobileScanner(
  controller: controller,
)

Additional Features

• Custom Scan Window: Define a specific area within the camera preview for scanning.
• Gallery Analysis: Retrieve barcodes from images in the device's gallery using analyzeImage().
• Image Capture: Obtain the captured image containing the barcode using returnImage: true in MobileScannerController options.

Conclusion

Mobile Scanner is a versatile tool for image recognition on mobile and desktop platforms. Its cross-platform compatibility, customizable options, and powerful features make it a valuable addition to any app that requires efficient and precise barcode scanning capabilities.