edge_detection 1.1.3

A flutter plugin to detect edges of objects, scan paper, detect corner, detect rectangle. It allows cropping of the detected object image and returns the path of the cropped image.

example/lib/main.dart

import 'dart:async';
import 'dart:io';
import 'package:edge_detection/edge_detection.dart';
import 'package:flutter/material.dart';
import 'package:path/path.dart';
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String? _imagePath;

  @override
  void initState() {
    super.initState();
  }

  Future<void> getImageFromCamera() async {
    bool isCameraGranted = await Permission.camera.request().isGranted;
    if (!isCameraGranted) {
      isCameraGranted =
          await Permission.camera.request() == PermissionStatus.granted;
    }

    if (!isCameraGranted) {
      // Have not permission to camera
      return;
    }

    // Generate filepath for saving
    String imagePath = join((await getApplicationSupportDirectory()).path,
        "${(DateTime.now().millisecondsSinceEpoch / 1000).round()}.jpeg");
      
    bool success = false;

    try {
      //Make sure to await the call to detectEdge.
      success = await EdgeDetection.detectEdge(
        imagePath,
        canUseGallery: true,
        androidScanTitle: 'Scanning', // use custom localizations for android
        androidCropTitle: 'Crop',
        androidCropBlackWhiteTitle: 'Black White',
        androidCropReset: 'Reset',
      );
      print("success: $success");
    } catch (e) {
      print(e);
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      if(success){
        _imagePath = imagePath;
      }
    });
  }

  Future<void> getImageFromGallery() async {
    // Generate filepath for saving
    String imagePath = join((await getApplicationSupportDirectory()).path,
        "${(DateTime.now().millisecondsSinceEpoch / 1000).round()}.jpeg");

    bool success = false;
    try {
      //Make sure to await the call to detectEdgeFromGallery.
      success = await EdgeDetection.detectEdgeFromGallery(
        imagePath,
        androidCropTitle: 'Crop', // use custom localizations for android
        androidCropBlackWhiteTitle: 'Black White',
        androidCropReset: 'Reset',
      );
      print("success: $success");
    } catch (e) {
      print(e);
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      if(success){
        _imagePath = imagePath;
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Plugin example app'),
        ),
        body: SingleChildScrollView(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              Center(
                child: ElevatedButton(
                  onPressed: getImageFromCamera,
                  child: Text('Scan'),
                ),
              ),
              SizedBox(height: 20),
              Center(
                child: ElevatedButton(
                  onPressed: getImageFromGallery,
                  child: Text('Upload'),
                ),
              ),
              SizedBox(height: 20),
              Text('Cropped image path:'),
              Padding(
                padding: const EdgeInsets.only(top: 0, left: 0, right: 0),
                child: Text(
                  _imagePath.toString(),
                  textAlign: TextAlign.center,
                  style: TextStyle(fontSize: 14),
                ),
              ),
              Visibility(
                visible: _imagePath != null,
                child: Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: Image.file(
                    File(_imagePath ?? ''),
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}