Face Liveness Detection Plus

A real-time facial verification package for Flutter using Google ML Kit for liveness detection. It ensures user interaction through smiling, blinking, and head movements. Key capabilities include real-time face detection, dynamic UI feedback, countdown timers, manual/programmatic capture control via FaceCaptureController, and image path retrieval for secure authentication and anti-spoofing verification.

Features

• Real-Time Detection: Fast and accurate face detection powered by Google ML Kit with configurable performanceMode (fast or accurate).
• Configurable Thresholds: Customize sensitivity thresholds for smiling, blinking, and head movements via LivenessThresholds.
• Localization & Instructions: Easily customize or translate instruction texts via LivenessLocalization.
• Custom UI Overlay: Replace default dotted border with custom customOverlayBuilder.
• Liveness Controller: Isolated logic and state controller LivenessDetectionController for testing and custom UI integration.
• Dynamic Feedback: Real-time visual UI feedback for each verification rule.
• Animated Transitions: Smooth progress animations during rule evaluation.
• Countdown Timer: Built-in countdown timer before verification completes.
• Capture Controller: Flexible manual or automatic image capture control (FaceCaptureController).
• Accuracy Calculation: Computes confidence/accuracy percentage per completed rule.

Installation

Add face_liveness_detection_plus to your pubspec.yaml:

dependencies:
  face_liveness_detection_plus: ^1.2.0

Run flutter pub get to install the package.

Platform Setup

iOS

Set your global platform target in ios/Podfile:

platform :ios, '15.5'

Add camera and microphone permission descriptions to ios/Runner/Info.plist:

<key>NSCameraUsageDescription</key>
<string>Camera access is required for real-time face liveness detection.</string>
<key>NSMicrophoneUsageDescription</key>
<string>Microphone access is required for video recording during verification.</string>

Preview

Usage Example

Basic Verification View

import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';
import 'package:face_liveness_detection_plus/face_liveness_detection_plus.dart';

class FaceVerificationWidget extends StatefulWidget {
  const FaceVerificationWidget({super.key});

  @override
  State<FaceVerificationWidget> createState() => _FaceVerificationWidgetState();
}

class _FaceVerificationWidgetState extends State<FaceVerificationWidget> {
  final List<Rulesets> _completedRuleset = [];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: FaceDetectorView(
        onSuccessValidation: (validated) {},
        onValidationDone: (controller) => const Center(
          child: Text('Verification Complete!'),
        ),
        onRulesetCompleted: (ruleset, imageUrl) {
          if (!_completedRuleset.contains(ruleset)) {
            setState(() => _completedRuleset.add(ruleset));
          }
        },
        child: ({required countdown, required state, required hasFace}) {
          return Column(
            children: [
              const SizedBox(height: 20),
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  const Icon(Icons.face, size: 30),
                  const SizedBox(width: 10),
                  Text(
                    hasFace ? 'User face found' : 'User face not found',
                    style: _textStyle,
                  ),
                ],
              ),
              const SizedBox(height: 30),
              Text(
                _rulesetHints[state] ?? 'Please follow instructions',
                style: _textStyle.copyWith(fontSize: 20, fontWeight: FontWeight.w600),
              ),
              if (countdown > 0)
                Text(
                  'Timer: $countdown',
                  style: _textStyle.copyWith(fontSize: 16),
                )
              else
                const CupertinoActivityIndicator(),
            ],
          );
        },
      ),
    );
  }
}

const TextStyle _textStyle = TextStyle(
  color: Colors.black,
  fontWeight: FontWeight.w400,
  fontSize: 12,
);

const Map<Rulesets, String> _rulesetHints = {
  Rulesets.smiling: 'Please Smile',
  Rulesets.blink: 'Please Blink',
  Rulesets.tiltUp: 'Please Look Up',
  Rulesets.tiltDown: 'Please Look Down',
  Rulesets.toLeft: 'Please Look Left',
  Rulesets.toRight: 'Please Look Right',
};

Manual Capture using FaceCaptureController

final FaceCaptureController _controller = FaceCaptureController();

FaceDetectorView(
  autoCapture: false,
  controller: _controller,
  onRulesetCompleted: (rule, imageUrl) {
    print('Completed rule: $rule, image: $imageUrl');
  },
  onValidationDone: (controller) => Container(),
  child: ({required countdown, required state, required hasFace}) {
    return ElevatedButton(
      onPressed: () async {
        final result = await _controller.capture(null);
        print('Captured ${result.rule} with accuracy ${result.accuracyPercentage}%');
      },
      child: const Text('Capture Image'),
    );
  },
)

Credits

This package is based on and inspired by the original work of Roshan Karki (facelivenessdetection). Special thanks for the core implementation of Flutter face liveness detection.

License

This project is licensed under the MIT License.