使用 Dart 与 Tesseract 实现验证码识别

一、环境准备

1. 安装 Dart SDK
   Windows/macOS/Linux 可从 https://dart.dev/get-dart 下载并安装。

2. 安装 Tesseract OCR
   更多内容访问ttocr.com或联系1436423940

Ubuntu / Debian

sudo apt install tesseract-ocr

macOS

brew install tesseract
二、新建项目

dart create -t console captcha_ocr
cd captcha_ocr
三、编辑 bin/captcha_ocr.dart

import 'dart:io';

void main(List arguments) async {
if (arguments.length != 1) {
print('用法: dart run bin/captcha_ocr.dart <图片路径>');
exit(1);
}

final imagePath = arguments[0];
final file = File(imagePath);

if (!file.existsSync()) {
print('文件不存在: $imagePath');
exit(1);
}

final tempBase = 'output_temp';
final whitelist = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';

final result = await Process.run('tesseract', [
imagePath,
tempBase,
'-l',
'eng',
'-c',
'tessedit_char_whitelist=$whitelist',
]);

if (result.exitCode != 0) {
print('Tesseract 执行失败:\n${result.stderr}');
exit(1);
}

final textFile = File('$tempBase.txt');
if (!textFile.existsSync()) {
print('未找到输出文件');
exit(1);
}

final raw = await textFile.readAsString();
final cleaned = raw.replaceAll(RegExp(r'[^A-Z0-9]'), '');

print('识别结果: $cleaned');

await textFile.delete();
}
四、运行示例

dart run bin/captcha_ocr.dart ./code1.png
输出示例：

识别结果: B8WQ