feat: Add document scanner package

packages/paperless_document_scanner/lib/modules/image_processing.dart

@@ -0,0 +1,112 @@
+import 'dart:ffi';
+import 'dart:io';
+import 'dart:typed_data';
+
+import 'package:ffi/ffi.dart';
+import 'package:paperless_document_scanner/types/edge_detection_result.dart';
+
+final DynamicLibrary _nativeInteropLib = Platform.isAndroid
+    ? DynamicLibrary.open("libnative_edge_detection.so")
+    : DynamicLibrary.process();
+
+class ImageProcessing {
+  static Future<bool> processImageFromFile(
+    String path,
+    EdgeDetectionResult result,
+  ) async {
+    final processImage = _nativeInteropLib
+        .lookup<NativeFunction<_c_process_image_from_file>>(
+            "process_image_from_file")
+        .asFunction<_dart_process_image_from_file>();
+
+    return processImage(
+          path.toNativeUtf8(),
+          result.topLeft.dx,
+          result.topLeft.dy,
+          result.topRight.dx,
+          result.topRight.dy,
+          result.bottomLeft.dx,
+          result.bottomLeft.dy,
+          result.bottomRight.dx,
+          result.bottomRight.dy,
+        ) ==
+        1;
+  }
+
+  static Future<bool> processImage(
+    Uint8List bytes,
+    EdgeDetectionResult result,
+  ) async {
+    final processImage = _nativeInteropLib
+        .lookup<NativeFunction<_c_process_image>>("process_image")
+        .asFunction<_dart_process_image>();
+
+    final imgBuffer = malloc.allocate<Uint8>(bytes.lengthInBytes);
+    Uint8List buffer = imgBuffer.asTypedList(bytes.lengthInBytes);
+    buffer.setAll(0, bytes);
+
+    return processImage(
+          imgBuffer,
+          bytes.lengthInBytes,
+          result.topLeft.dx,
+          result.topLeft.dy,
+          result.topRight.dx,
+          result.topRight.dy,
+          result.bottomLeft.dx,
+          result.bottomLeft.dy,
+          result.bottomRight.dx,
+          result.bottomRight.dy,
+        ) ==
+        1;
+  }
+}
+
+typedef _c_process_image_from_file = Int8 Function(
+  Pointer<Utf8> imagePath,
+  Double topLeftX,
+  Double topLeftY,
+  Double topRightX,
+  Double topRightY,
+  Double bottomLeftX,
+  Double bottomLeftY,
+  Double bottomRightX,
+  Double bottomRightY,
+);
+
+typedef _c_process_image = Int8 Function(
+  Pointer<Uint8> imagePath,
+  Int32 byteSize,
+  Double topLeftX,
+  Double topLeftY,
+  Double topRightX,
+  Double topRightY,
+  Double bottomLeftX,
+  Double bottomLeftY,
+  Double bottomRightX,
+  Double bottomRightY,
+);
+
+typedef _dart_process_image_from_file = int Function(
+  Pointer<Utf8> imagePath,
+  double topLeftX,
+  double topLeftY,
+  double topRightX,
+  double topRightY,
+  double bottomLeftX,
+  double bottomLeftY,
+  double bottomRightX,
+  double bottomRightY,
+);
+
+typedef _dart_process_image = int Function(
+  Pointer<Uint8> imagePath,
+  int byteSize,
+  double topLeftX,
+  double topLeftY,
+  double topRightX,
+  double topRightY,
+  double bottomLeftX,
+  double bottomLeftY,
+  double bottomRightX,
+  double bottomRightY,
+);