# FingerScanner

A Flutter biometric capture app demonstrating Clean Architecture and Riverpod.

## Features

- **Camera Preview**: Real-time camera feed using the `camera` package.
- **Real-time Quality Analysis**: 
    - **Throttled Stream**: Processes camera frames at ~6-7 FPS.
    - **Background Isolate**: Offloads heavy image processing to a background thread to keep UI smooth.
    - **Quality Checks**:
        - **Sharpness**: Laplacian variance.
        - **Brightness**: Mean pixel intensity.
        - **Presence**: ROI standard deviation check.
- **Dynamic UI Guide**: Visual guide changes color (Red/Green) based on analysis results.
- **Clean Architecture**: Separation of concerns into Core, Data, Domain, and Presentation layers.
- **State Management**: Powered by `flutter_riverpod` (Notifier).

## Getting Started

1.  **Install Dependencies**:
    ```bash
    flutter pub get
    ```

2.  **Run on Device**:
    Connect a physical device (Camera is not supported on iOS Simulator).
    ```bash
    flutter run
    ```

## Permissions

- **iOS**: `NSCameraUsageDescription` and `NSMicrophoneUsageDescription` are added to `Info.plist`.
- **Android**: `android.permission.CAMERA` is added to `AndroidManifest.xml`.

## Architecture

- **Domain Layer**: Entities (`ScanResult`, `QualityStatus`), Repositories (Interface), UseCases (`ScanFingerprint`).
- **Data Layer**: DataSources (`CameraDataSource`), Repository Implementation.
- **Presentation Layer**: Riverpod Providers (`ScannerNotifier`), Screens (`ScannerScreen`), Widgets (`CameraPreviewWidget`, `FingerprintGuidePainter`).
- **Core**: Services (`ImageProcessorIsolate` using `opencv_dart`).# finger_print