feat: Add document scanner package

2025-12-12 03:10:39 -06:00 · 2023-02-22 18:17:50 +01:00
parent a8a41b38a8
commit 9c5a45f329
105 changed files with 3998 additions and 0 deletions
--- a/packages/paperless_document_scanner/example/lib/main.dart
+++ b/packages/paperless_document_scanner/example/lib/main.dart
@@ -0,0 +1,113 @@
+import 'dart:typed_data';
+
+import 'package:camera/camera.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:image/image.dart' as imglib;
+import 'scan.dart';
+
+late final List<CameraDescription> cameras;
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+  cameras = await availableCameras();
+  runApp(const EdgeDetectionApp());
+}
+
+class EdgeDetectionApp extends StatefulWidget {
+  const EdgeDetectionApp({super.key});
+
+  @override
+  State<EdgeDetectionApp> createState() => _EdgeDetectionAppState();
+}
+
+class _EdgeDetectionAppState extends State<EdgeDetectionApp> {
+  CameraImage? _image;
+  late final CameraController _controller;
+
+  @override
+  void initState() {
+    super.initState();
+
+    () async {
+      _controller = CameraController(
+        cameras
+            .where(
+                (element) => element.lensDirection == CameraLensDirection.back)
+            .first,
+        ResolutionPreset.low,
+        enableAudio: false,
+      );
+      await _controller.initialize();
+      _controller.startImageStream((image) {
+        setState(() => _image = image);
+      });
+    }();
+  }
+
+  Uint8List concatenatePlanes(List<Plane> planes) {
+    final WriteBuffer allBytes = WriteBuffer();
+    for (final plane in planes) {
+      allBytes.putUint8List(plane.bytes);
+    }
+    return allBytes.done().buffer.asUint8List();
+  }
+
+  Image convertYUV420toImageColor(CameraImage image) {
+    final int width = image.width;
+    final int height = image.height;
+    final int uvRowStride = image.planes[1].bytesPerRow;
+    final int uvPixelStride = image.planes[1].bytesPerPixel!;
+
+    print("uvRowStride: " + uvRowStride.toString());
+    print("uvPixelStride: " + uvPixelStride.toString());
+
+    // imgLib -> Image package from https://pub.dartlang.org/packages/image
+    var img = imglib.Image(
+      width: width,
+      height: height,
+    ); // Create Image buffer
+
+    // Fill image buffer with plane[0] from YUV420_888
+    for (int x = 0; x < width; x++) {
+      for (int y = 0; y < height; y++) {
+        final int uvIndex =
+            uvPixelStride * (x / 2).floor() + uvRowStride * (y / 2).floor();
+        final int index = y * width + x;
+
+        final yp = image.planes[0].bytes[index];
+        final up = image.planes[1].bytes[uvIndex];
+        final vp = image.planes[2].bytes[uvIndex];
+        // Calculate pixel color
+        int r = (yp + vp * 1436 / 1024 - 179).round().clamp(0, 255);
+        int g = (yp - up * 46549 / 131072 + 44 - vp * 93604 / 131072 + 91)
+            .round()
+            .clamp(0, 255);
+        int b = (yp + up * 1814 / 1024 - 227).round().clamp(0, 255);
+        // color: 0x FF  FF  FF  FF
+        //           A   B   G   R
+        img.data?.setPixelRgb(x, y, r, g, b);
+      }
+    }
+
+    imglib.PngEncoder pngEncoder = new imglib.PngEncoder(level: 0);
+    final png = pngEncoder.encode(img);
+    return Image.memory(png);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Flutter Demo',
+      theme: ThemeData(
+        visualDensity: VisualDensity.adaptivePlatformDensity,
+      ),
+      home: Scaffold(
+        body: Center(
+          child: _image != null
+              ? convertYUV420toImageColor(_image!)
+              : Placeholder(),
+        ),
+      ),
+    );
+  }
+}