Flutter人脸识别插件flutter_face_api的使用

Regula Face SDK plugin for Flutter

Face SDK是一个用于面部匹配、识别和活体检测的框架。它提供了强大的功能，可以帮助开发者在他们的应用程序中实现高效的人脸识别能力。

文档

你可以在这里找到更多文档：Regula Face SDK Documentation

支持

如果你需要任何帮助或想要报告错误/提出改进建议，请不要犹豫联系我们的支持团队：Contact Support

示例代码与完整Demo

以下是一个完整的示例，演示了如何使用flutter_face_api插件进行人脸匹配和活体检测。

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_face_api/flutter_face_api.dart';
import 'package:image_picker/image_picker.dart';

void main() => runApp(new MaterialApp(home: new MyApp()));

class _MyAppState extends State<MyApp> {
  var faceSdk = FaceSDK.instance;

  // 状态信息
  String _status = "nil";
  String _similarityStatus = "nil";
  String _livenessStatus = "nil";

  // 图像展示
  Image _uiImage1 = Image.asset('assets/images/portrait.png');
  Image _uiImage2 = Image.asset('assets/images/portrait.png');

  // 设置状态信息
  set status(String val) => setState(() => _status = val);
  set similarityStatus(String val) => setState(() => _similarityStatus = val);
  set livenessStatus(String val) => setState(() => _livenessStatus = val);
  set uiImage1(Image val) => setState(() => _uiImage1 = val);
  set uiImage2(Image val) => setState(() => _uiImage2 = val);

  MatchFacesImage? mfImage1;
  MatchFacesImage? mfImage2;

  @override
  void initState() {
    super.initState();
    SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
    init();
  }

  // 初始化SDK
  Future<bool> initialize() async {
    status = "Initializing...";
    var license = await loadAssetIfExists("assets/regula.license");
    InitConfig? config = null;
    if (license != null) config = InitConfig(license);
    var (success, error) = await faceSdk.initialize(config: config);
    if (!success) {
      status = error!.message;
      print("${error.code}: ${error.message}");
    } else {
      status = "Ready";
    }
    return success;
  }

  // 加载资产文件（如果存在）
  Future<ByteData?> loadAssetIfExists(String path) async {
    try {
      return await rootBundle.load(path);
    } catch (_) {
      return null;
    }
  }

  // 开始活体检测
  startLiveness() async {
    var result = await faceSdk.startLiveness(
      config: LivenessConfig(skipStep: [LivenessSkipStep.ONBOARDING_STEP]),
      notificationCompletion: (notification) {
        print(notification.status);
      },
    );
    if (result.image == null) return;
    setImage(result.image!, ImageType.LIVE, 1);
    livenessStatus = result.liveness.name.toLowerCase();
  }

  // 匹配人脸
  matchFaces() async {
    if (mfImage1 == null || mfImage2 == null) {
      status = "Both images required!";
      return;
    }
    status = "Processing...";
    var request = MatchFacesRequest([mfImage1!, mfImage2!]);
    var response = await faceSdk.matchFaces(request);
    var split = await faceSdk.splitComparedFaces(response.results, 0.75);
    var match = split.matchedFaces;
    similarityStatus = "failed";
    if (match.isNotEmpty) {
      similarityStatus = (match[0].similarity * 100).toStringAsFixed(2) + "%";
    }
    status = "Ready";
  }

  // 清除结果
  clearResults() {
    status = "Ready";
    similarityStatus = "nil";
    livenessStatus = "nil";
    uiImage2 = Image.asset('assets/images/portrait.png');
    uiImage1 = Image.asset('assets/images/portrait.png');
    mfImage1 = null;
    mfImage2 = null;
  }

  // 设置图像
  setImage(Uint8List bytes, ImageType type, int number) {
    similarityStatus = "nil";
    var mfImage = MatchFacesImage(bytes, type);
    if (number == 1) {
      mfImage1 = mfImage;
      uiImage1 = Image.memory(bytes);
      livenessStatus = "nil";
    }
    if (number == 2) {
      mfImage2 = mfImage;
      uiImage2 = Image.memory(bytes);
    }
  }

  // 使用图库选择图片
  Widget useGallery(int number) {
    return TextButton(
      child: Text("Use gallery"),
      onPressed: () async {
        Navigator.pop(context);
        var image = await ImagePicker().pickImage(source: ImageSource.gallery);
        if (image != null) {
          setImage(File(image.path).readAsBytesSync(), ImageType.PRINTED, number);
        }
      },
    );
  }

  // 使用相机拍摄照片
  Widget useCamera(int number) {
    return TextButton(
      child: Text("Use camera"),
      onPressed: () async {
        Navigator.pop(context);
        var response = await faceSdk.startFaceCapture();
        var image = response.image;
        if (image != null) setImage(image.image, image.imageType, number);
      },
    );
  }

  // 显示图像
  Widget image(Image image, Function() onTap) => GestureDetector(
        onTap: onTap,
        child: Image(height: 150, width: 150, image: image.image),
      );

  // 创建按钮
  Widget button(String text, Function() onPressed) {
    return Container(
      child: TextButton(
        child: Text(text),
        onPressed: onPressed,
        style: ButtonStyle(
          backgroundColor: MaterialStateProperty.all<Color>(Colors.black12),
        ),
      ),
      width: 250,
    );
  }

  // 创建文本
  Widget text(String text) => Text(text, style: TextStyle(fontSize: 18));

  // 创建对话框选项
  Widget setImageDialog(BuildContext context, int number) => showDialog(
        context: context,
        builder: (BuildContext context) => AlertDialog(
          title: Text("Select option"),
          actions: [useGallery(number), useCamera(number)],
        ),
      );

  @override
  Widget build(BuildContext bc) {
    return Scaffold(
      appBar: AppBar(title: Center(child: Text(_status))),
      body: Container(
        margin: EdgeInsets.fromLTRB(0, 0, 0, MediaQuery.of(bc).size.height / 8),
        width: double.infinity,
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            image(_uiImage1, () => setImageDialog(bc, 1)),
            image(_uiImage2, () => setImageDialog(bc, 2)),
            Container(margin: EdgeInsets.fromLTRB(0, 0, 0, 15)),
            button("Match", () => matchFaces()),
            button("Liveness", () => startLiveness()),
            button("Clear", () => clearResults()),
            Container(margin: EdgeInsets.fromLTRB(0, 15, 0, 0)),
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                text("Similarity: " + _similarityStatus),
                Container(margin: EdgeInsets.fromLTRB(20, 0, 0, 0)),
                text("Liveness: " + _livenessStatus)
              ],
            )
          ],
        ),
      ),
    );
  }
}

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

关键点解释

• 初始化：通过initialize方法初始化Face SDK，如果有许可证文件则加载许可证以启用离线匹配。
• 活体检测：使用startLiveness方法启动活体检测流程。
• 人脸匹配：使用matchFaces方法对两张人脸图像进行匹配，并显示相似度百分比。
• 图像选择：用户可以选择从图库或相机获取图像，然后进行处理和匹配。
• UI设计：使用Flutter的Scaffold、AppBar等组件构建了一个简单的用户界面，包括两个用于显示图像的区域和三个按钮（匹配、活体检测、清除）。

这个示例展示了如何在Flutter应用中集成和使用flutter_face_api插件来实现基本的人脸识别功能。根据实际需求，您可以进一步扩展和完善此示例。