Swipe Image OCR

A Flutter package that provides interactive image cropping and text recognition functionality using Google ML Kit. Users can draw selection areas on images by swiping their finger, and the package automatically crops the selected area and performs OCR text recognition.

Example GIF

Features

  • 🎯 Interactive Image Cropping: Draw selection areas by swiping across images
  • 🔍 OCR Text Recognition: Automatic text extraction using Google ML Kit
  • ⚡ Performance Optimized: Heavy operations run on isolates to keep UI responsive
  • 🎨 Customizable UI: Configurable stroke width, colors, and border radius
  • 📱 Cross Platform: Supports both Android and iOS
  • 🛡️ Error Handling: Comprehensive error handling with callbacks

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  swipe_image_ocr: ^0.0.1+1

Then run:

flutter pub get

Usage

Basic Usage

import 'package:swipe_image_ocr/swipe_image_ocr.dart';
import 'dart:typed_data';

SwipeImageOCR(
  imageBytes: yourImageBytes, // Uint8List
  onSwipeImage: (File? file) {
    print('Cropped image saved to: ${file?.path}');
  },
  onTextRead: (String? text) {
    print('Recognized text: $text');
  },
  onErrorRead: (Object error, StackTrace? stackTrace) {
    print('Error occurred: $error');
  },
)

Advanced Usage with Customization

SwipeImageOCR(
  imageBytes: imageBytes,
  borderRadius: BorderRadius.circular(12),
  strokeWidth: 20.0,
  swipeColor: Colors.blue.withOpacity(0.7),
  indicatorColor: Colors.red,
  onSwipeImage: (File? file) {
    // Handle cropped image
    if (file != null) {
      // Process the cropped image
      processCroppedImage(file);
    }
  },
  onTextRead: (String? text) {
    // Handle recognized text
    if (text != null && text.isNotEmpty) {
      setState(() {
        recognizedText = text;
      });
    }
  },
  onErrorRead: (Object error, StackTrace? stackTrace) {
    // Handle errors
    showErrorDialog(error.toString());
  },
)

API Reference

SwipeImageOCR

The main widget that provides the interactive image cropping and OCR functionality.

Constructor

SwipeImageOCR({
  Key? key,
  required Uint8List imageBytes,
  BorderRadiusGeometry? borderRadius,
  Function(File?)? onSwipeImage,
  Function(String?)? onTextRead,
  Function(Object, StackTrace)? onErrorRead,
  double strokeWidth = 16.0,
  Color? swipeColor,
  Color? indicatorColor,
})

Parameters

Parameter Type Description Default
imageBytes Uint8List The image data to display and crop Required
borderRadius BorderRadiusGeometry? Border radius for the widget container null
onSwipeImage Function(File?)? Callback when image is successfully cropped null
onTextRead Function(String?)? Callback when text is successfully recognized null
onErrorRead Function(Object, StackTrace)? Callback when an error occurs null
strokeWidth double Width of the swipe stroke 16.0
swipeColor Color? Color of the swipe path null (uses theme)
indicatorColor Color? Color of the selection indicator null (uses theme)

Callbacks

  • onSwipeImage: Called when the user completes drawing a selection area and the image is successfully cropped. Receives a File object containing the cropped image, or null if cropping failed.

  • onTextRead: Called when text recognition is successfully completed. Receives a String containing the recognized text, or null if text recognition failed.

  • onErrorRead: Called when an error occurs during text recognition. Receives the error object and optional stack trace for debugging.

Requirements

  • Flutter SDK >= 3.3.0
  • Dart SDK >= 3.9.0
  • Android API level 21+ (Android 5.0)
  • iOS 11.0+

Dependencies

This package uses the following dependencies:

  • google_mlkit_text_recognition: For OCR text recognition
  • google_mlkit_barcode_scanning: For barcode scanning capabilities
  • image: For image processing operations
  • path_provider: For file system operations

Example

Check out the example directory for a complete implementation example.

To run the example:

cd example
flutter run

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

If you encounter any issues or have questions, please file an issue on the GitHub repository.

Changelog

See CHANGELOG.md for a list of changes and version history.

Libraries

swipe_image_ocr