Files
MoneyMgr/moneymgr_mobile/lib/utils/ocr_utils.dart

45 lines
1.4 KiB
Dart

import 'dart:math';
import 'dart:typed_data';
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
import 'package:google_mlkit_text_recognition/google_mlkit_text_recognition.dart';
import 'package:logging/logging.dart';
/// Attempt to extract total amount from invoice image
Future<double?> extractTotalFromBill(Uint8List imgBuff) async {
final decodedImage = await decodeImageFromList(imgBuff);
final byteData = await decodedImage.toByteData(
format: ui.ImageByteFormat.rawRgba,
);
final image = InputImage.fromBitmap(
bitmap: byteData!.buffer.asUint8List(),
width: decodedImage.width,
height: decodedImage.height,
);
final textRecognizer = TextRecognizer(script: TextRecognitionScript.latin);
final extractionResult = await textRecognizer.processImage(image);
Logger.root.fine("Expense text: ${extractionResult.text}");
// Check for highest amount on invoice
final regexp = RegExp(
r'([0-9]+([ ]*(\\.|,)[ ]*[0-9]{1,2}){0,1})[ \\t\\n]*(EUR|eur|€)',
multiLine: true,
caseSensitive: false,
);
var highest = 0.0;
for (final match in regexp.allMatches(extractionResult.text)) {
if (match.groupCount == 0) continue;
// Process only numeric value
final value = (match.group(1) ?? "").replaceAll(",", ".");
highest = max(highest, double.tryParse(value) ?? 0.0);
}
return highest == 0.0 ? null : highest;
}