Q818 Device Fingerprint SDK Plugin for Flutter

This Flutter plugin provides a simple bridge to native Q818 fingerprint hardware SDKs using Platform Channels.
It allows developers to capture fingerprint images, generate templates (ISO/ANSI), and perform template matching.

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✨ Features

• Open and close the fingerprint device
• Capture fingerprint images
• Generate ISO and ANSI templates
• Compare fingerprint templates for matching
• Works with custom hardware SDKs via native integration (Java/Kotlin, Swift/Objective-C)

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📦 Installation

Add the dependency in your Flutter project:

dependencies:
  fingerprint_sdk:
    path: ./fingerprint_sdk

Then run:

flutter pub get

⸻

🚀 Usage

Import the plugin:

import 'package:fingerprint_sdk/fingerprint_sdk.dart';

Example

final sdk = FingerprintSdk();

// Open device
final handle = await sdk.openDevice();
print("Device Handle: $handle");

// Capture fingerprint image
final imageBase64 = await sdk.captureImage();
print("Captured Image (Base64): $imageBase64");

// Create ISO template
final isoTemplate = await sdk.createISOTemplate(imageBase64!);
print("ISO Template: $isoTemplate");

// Create ANSI template
final ansiTemplate = await sdk.createANSITemplate(imageBase64);
print("ANSI Template: $ansiTemplate");

// Compare templates
final score = await sdk.compareTemplates(isoTemplate!, ansiTemplate!);
print("Match Score: $score");

// Close device
await sdk.closeDevice();

⸻

📂 Project Structure

fingerprint_sdk/
├─ .dart_tool/
│  ├─ extension_discovery/
│  │  ├─ README.md
│  │  └─ vs_code.json
│  ├─ package_config.json
│  ├─ package_graph.json
│  └─ version
├─ android/
│  ├─ gradle/
│  │  └─ wrapper/
│  │     └─ gradle-wrapper.properties
│  ├─ src/
│  │  ├─ main/
│  │  │  ├─ java/
│  │  │  │  └─ com/
│  │  │  │     ├─ example/
│  │  │  │     │  └─ fingerprint_sdk/
│  │  │  │     │     └─ FingerprintSdkPlugin.java
│  │  │  │     └─ HZFINGER/
│  │  │  │        ├─ HAPI.java
│  │  │  │        ├─ HostUsb.java
│  │  │  │        └─ LAPI.java
│  │  │  ├─ jniLibs/
│  │  │  │  ├─ arm64-v8a/
│  │  │  │  │  ├─ libbiofp_e_lapi.so
│  │  │  │  │  ├─ libcheckLive.so
│  │  │  │  │  └─ libFingerILA.so
│  │  │  │  ├─ armeabi/
│  │  │  │  │  ├─ libbiofp_e_lapi.so
│  │  │  │  │  ├─ libcheckLive.so
│  │  │  │  │  └─ libFingerILA.so
│  │  │  │  └─ armeabi-v7a/
│  │  │  │     ├─ libbiofp_e_lapi.so
│  │  │  │     ├─ libcheckLive.so
│  │  │  │     └─ libFingerILA.so
│  │  │  ├─ kotlin/
│  │  │  │  └─ com/
│  │  │  │     └─ example/
│  │  │  │        └─ fingerprint_sdk/
│  │  │  │           ├─ FingerprintSdkPlugin.kt
│  │  │  │           └─ FingerprintSdkPlugin.txt
│  │  │  └─ AndroidManifest.xml
│  │  └─ test/
│  │     └─ kotlin/
│  │        └─ com/
│  │           └─ example/
│  │              └─ fingerprint_sdk/
│  │                 └─ FingerprintSdkPluginTest.kt
│  ├─ .gitignore
│  ├─ build.gradle
│  ├─ fingerprint_sdk_android.iml
│  ├─ local.properties
│  └─ settings.gradle
├─ example/
├─ lib/
│  ├─ fingerprint_sdk_method_channel.dart
│  ├─ fingerprint_sdk_platform_interface.dart
│  └─ fingerprint_sdk.dart
├─ test/
│  ├─ fingerprint_sdk_method_channel_test.dart
│  └─ fingerprint_sdk_test.dart
├─ .gitignore
├─ .metadata
├─ analysis_options.yaml
├─ CHANGELOG.md
├─ fingerprint_sdk.iml
├─ LICENSE
├─ pubspec.lock
├─ pubspec.yaml
└─ README.md

⸻

⚙️ API Reference

Method	Parameters	Returns	Description
openDevice()	none	Future<int?>	Opens the fingerprint device, returning a handle or null if it fails.
captureImage()	none	Future<String?>	Captures a fingerprint image and returns it as a Base64-encoded string.
createISOTemplate()	String imageBase64	Future<String?>	Generates an ISO fingerprint template from a captured image.
createANSITemplate()	String imageBase64	Future<String?>	Generates an ANSI fingerprint template from a captured image.
compareTemplates()	String t1, String t2	Future<int?>	Compares two templates and returns a similarity score.
closeDevice()	none	Future<int?>	Closes the fingerprint device.

🔧 Platform Support

• Android: Implemented via FingerprintSdkPlugin.java
• iOS: Implementation pending (Swift/Objective-C)

🛠 Development Notes

• Ensure native SDK libraries required by your fingerprint hardware (such as .so, .dll, or .framework files) are correctly integrated into your Android/iOS projects.
• This plugin communicates between Dart and native code using Flutter’s MethodChannel (fingerprint_sdk).
• The ISO and ANSI templates are returned as Base64-encoded strings for easy storage and transmission.

🖼 Workflow Overview

Fingerprint Device
↓
Capture Image (Base64)
↓
Generate Template (ISO / ANSI)
↓
Store or Compare Templates

📄 License

This project is licensed under the MIT License. Use it at your own risk and ensure compliance with your hardware vendor’s SDK terms.