# AI-Powered Face Recognition & Auto-Sorting System

**Created**: 2025-10-31
**Status**: Planning Phase
**Target Version**: 6.5.0

---

## 📋 Overview

Automatic face recognition and sorting system that processes downloaded images, identifies people, and organizes them into person-specific directories. Unknown faces go to a review queue for manual identification.

---

## 🎯 Goals

### Primary Goals
1. **Automatic face detection** - Identify faces in downloaded images
2. **Face recognition** - Match faces against known people database
3. **Auto-sorting** - Move matched images to person-specific directories
4. **Review queue** - Queue unknown faces for manual identification
5. **Learning system** - Improve recognition from manual reviews

### Secondary Goals
6. **Multi-face support** - Handle images with multiple people
7. **Confidence scoring** - Only auto-sort high confidence matches
8. **Performance** - Process images quickly without blocking downloads
9. **Privacy** - All processing done locally (no cloud APIs)
10. **Immich integration** - Sync sorted images to Immich

---

## 🏗️ Architecture

### High-Level Flow

```
┌─────────────────┐
│  Image Download │
│    Complete     │
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│  Face Detection │ ◄── Uses face_recognition library
│   (Find Faces)  │     or DeepFace
└────────┬────────┘
         │
         ├─── No faces found ──► Skip (keep in original location)
         │
         ▼
┌─────────────────┐
│ Face Recognition│ ◄── Compare against known faces DB
│  (Identify Who) │
└────────┬────────┘
         │
         ├─── High confidence match ──► Auto-sort to person directory
         │
         ├─── Low confidence/Multiple ──► Review Queue
         │
         └─── Unknown face ──────────► Review Queue
```

### Database Schema

```sql
-- New table: face_recognition_people
CREATE TABLE face_recognition_people (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT NOT NULL UNIQUE,
    directory TEXT NOT NULL,  -- Target directory for this person
    face_encodings BLOB,       -- Stored face encodings (multiple per person)
    created_at TEXT,
    updated_at TEXT,
    enabled INTEGER DEFAULT 1
);

-- New table: face_recognition_queue
CREATE TABLE face_recognition_queue (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    download_id INTEGER,
    file_path TEXT NOT NULL,
    thumbnail_path TEXT,
    face_encoding BLOB,         -- Encoding of the face found
    face_location TEXT,          -- JSON: bounding box coordinates
    confidence REAL,             -- Match confidence if any
    suggested_person_id INTEGER, -- Best match suggestion
    status TEXT DEFAULT 'pending', -- pending, reviewed, skipped
    created_at TEXT,
    reviewed_at TEXT,
    reviewed_by TEXT,
    FOREIGN KEY (download_id) REFERENCES downloads(id),
    FOREIGN KEY (suggested_person_id) REFERENCES face_recognition_people(id)
);

-- New table: face_recognition_history
CREATE TABLE face_recognition_history (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    download_id INTEGER,
    file_path TEXT NOT NULL,
    person_id INTEGER,
    confidence REAL,
    action TEXT,  -- auto_sorted, manually_sorted, skipped
    processed_at TEXT,
    FOREIGN KEY (download_id) REFERENCES downloads(id),
    FOREIGN KEY (person_id) REFERENCES face_recognition_people(id)
);
```

### Directory Structure

```
/mnt/storage/Downloads/
├── [existing platform directories]/
│   └── [original downloads]
│
├── faces/
│   ├── person1_name/
│   │   ├── 20250131_120000_abc123.jpg
│   │   └── 20250131_130000_def456.jpg
│   │
│   ├── person2_name/
│   │   └── 20250131_140000_ghi789.jpg
│   │
│   └── review_queue/
│       ├── unknown_face_20250131_120000_abc123.jpg
│       ├── low_confidence_20250131_130000_def456.jpg
│       └── multiple_faces_20250131_140000_ghi789.jpg
```

---

## 🔧 Technical Implementation

### 1. Face Recognition Library Options

#### Option A: face_recognition (Recommended)
**Pros**:
- Built on dlib (very accurate)
- Simple Python API
- Fast face detection and recognition
- Well-documented
- Works offline

**Cons**:
- Requires dlib compilation (can be slow to install)
- Heavy dependencies

**Installation**:
```bash
pip3 install face_recognition
pip3 install pillow
```

**Usage Example**:
```python
import face_recognition
import numpy as np

# Load and encode known face
image = face_recognition.load_image_file("person1.jpg")
encoding = face_recognition.face_encodings(image)[0]

# Compare with new image
unknown_image = face_recognition.load_image_file("unknown.jpg")
unknown_encodings = face_recognition.face_encodings(unknown_image)

matches = face_recognition.compare_faces([encoding], unknown_encodings[0])
distance = face_recognition.face_distance([encoding], unknown_encodings[0])
```

#### Option B: DeepFace
**Pros**:
- Multiple backend models (VGG-Face, Facenet, OpenFace, DeepID, ArcFace)
- Very high accuracy
- Age, gender, emotion detection

**Cons**:
- Slower than face_recognition
- More complex setup
- Larger dependencies

#### Option C: OpenCV + dlib
**Pros**:
- Already installed (OpenCV used elsewhere)
- Full control
- Fast face detection

**Cons**:
- More manual coding
- Complex face encoding

**Recommendation**: Start with **face_recognition** (Option A) for best balance.

---

### 2. Core Module Structure

#### New File: `modules/face_recognition_manager.py`

```python
#!/usr/bin/env python3
"""
Face Recognition Manager
Handles face detection, recognition, and auto-sorting
"""

import os
import json
import logging
import pickle
import shutil
import sqlite3
from pathlib import Path
from datetime import datetime
from typing import List, Dict, Optional, Tuple

import face_recognition
import numpy as np
from PIL import Image

logger = logging.getLogger(__name__)


class FaceRecognitionManager:
    """Manages face recognition and auto-sorting"""

    def __init__(self, db_path: str, config: dict):
        self.db_path = db_path
        self.config = config

        # Configuration
        self.enabled = config.get('face_recognition', {}).get('enabled', False)
        self.confidence_threshold = config.get('face_recognition', {}).get('confidence_threshold', 0.6)
        self.auto_sort_threshold = config.get('face_recognition', {}).get('auto_sort_threshold', 0.5)
        self.base_directory = config.get('face_recognition', {}).get('base_directory', '/mnt/storage/Downloads/faces')
        self.review_queue_dir = os.path.join(self.base_directory, 'review_queue')

        # Create directories
        os.makedirs(self.base_directory, exist_ok=True)
        os.makedirs(self.review_queue_dir, exist_ok=True)

        # Initialize database tables
        self._init_database()

        # Load known faces into memory
        self.known_faces = {}  # person_id: [encodings]
        self._load_known_faces()

    def _init_database(self):
        """Create face recognition tables"""
        with sqlite3.connect(self.db_path) as conn:
            conn.execute("""
                CREATE TABLE IF NOT EXISTS face_recognition_people (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    name TEXT NOT NULL UNIQUE,
                    directory TEXT NOT NULL,
                    face_encodings BLOB,
                    created_at TEXT,
                    updated_at TEXT,
                    enabled INTEGER DEFAULT 1
                )
            """)

            conn.execute("""
                CREATE TABLE IF NOT EXISTS face_recognition_queue (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    download_id INTEGER,
                    file_path TEXT NOT NULL,
                    thumbnail_path TEXT,
                    face_encoding BLOB,
                    face_location TEXT,
                    confidence REAL,
                    suggested_person_id INTEGER,
                    status TEXT DEFAULT 'pending',
                    created_at TEXT,
                    reviewed_at TEXT,
                    reviewed_by TEXT,
                    FOREIGN KEY (download_id) REFERENCES downloads(id),
                    FOREIGN KEY (suggested_person_id) REFERENCES face_recognition_people(id)
                )
            """)

            conn.execute("""
                CREATE TABLE IF NOT EXISTS face_recognition_history (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    download_id INTEGER,
                    file_path TEXT NOT NULL,
                    person_id INTEGER,
                    confidence REAL,
                    action TEXT,
                    processed_at TEXT,
                    FOREIGN KEY (download_id) REFERENCES downloads(id),
                    FOREIGN KEY (person_id) REFERENCES face_recognition_people(id)
                )
            """)

            conn.commit()

    def _load_known_faces(self):
        """Load known face encodings from database"""
        with sqlite3.connect(self.db_path) as conn:
            cursor = conn.execute("""
                SELECT id, name, face_encodings
                FROM face_recognition_people
                WHERE enabled = 1
            """)

            for person_id, name, encodings_blob in cursor.fetchall():
                if encodings_blob:
                    encodings = pickle.loads(encodings_blob)
                    self.known_faces[person_id] = {
                        'name': name,
                        'encodings': encodings
                    }

        logger.info(f"Loaded {len(self.known_faces)} known people")

    def process_image(self, file_path: str, download_id: Optional[int] = None) -> Dict:
        """
        Process an image for face recognition

        Returns:
            dict: {
                'status': 'success'|'error'|'no_faces'|'skipped',
                'action': 'auto_sorted'|'queued'|'skipped',
                'person_id': int or None,
                'person_name': str or None,
                'confidence': float or None,
                'faces_found': int,
                'message': str
            }
        """
        if not self.enabled:
            return {'status': 'skipped', 'message': 'Face recognition disabled'}

        if not os.path.exists(file_path):
            return {'status': 'error', 'message': 'File not found'}

        # Only process image files
        ext = os.path.splitext(file_path)[1].lower()
        if ext not in ['.jpg', '.jpeg', '.png', '.heic', '.heif']:
            return {'status': 'skipped', 'message': 'Not an image file'}

        try:
            # Load image
            image = face_recognition.load_image_file(file_path)

            # Find faces
            face_locations = face_recognition.face_locations(image)

            if not face_locations:
                logger.debug(f"No faces found in {file_path}")
                return {
                    'status': 'no_faces',
                    'action': 'skipped',
                    'faces_found': 0,
                    'message': 'No faces detected'
                }

            # Get face encodings
            face_encodings = face_recognition.face_encodings(image, face_locations)

            # Handle multiple faces
            if len(face_encodings) > 1:
                return self._handle_multiple_faces(
                    file_path, download_id, face_encodings, face_locations
                )

            # Single face - try to match
            encoding = face_encodings[0]
            location = face_locations[0]

            match_result = self._find_best_match(encoding)

            if match_result and match_result['confidence'] >= self.auto_sort_threshold:
                # High confidence - auto sort
                return self._auto_sort_image(
                    file_path, download_id, match_result['person_id'],
                    match_result['confidence'], encoding, location
                )
            else:
                # Low confidence or no match - queue for review
                return self._queue_for_review(
                    file_path, download_id, encoding, location,
                    match_result['person_id'] if match_result else None,
                    match_result['confidence'] if match_result else None
                )

        except Exception as e:
            logger.error(f"Error processing {file_path}: {e}")
            return {'status': 'error', 'message': str(e)}

    def _find_best_match(self, face_encoding: np.ndarray) -> Optional[Dict]:
        """
        Find best matching person for a face encoding

        Returns:
            dict: {'person_id': int, 'name': str, 'confidence': float} or None
        """
        if not self.known_faces:
            return None

        best_match = None
        best_distance = float('inf')

        for person_id, person_data in self.known_faces.items():
            for known_encoding in person_data['encodings']:
                distance = face_recognition.face_distance([known_encoding], face_encoding)[0]

                if distance < best_distance:
                    best_distance = distance
                    best_match = {
                        'person_id': person_id,
                        'name': person_data['name'],
                        'confidence': 1.0 - distance  # Convert distance to confidence
                    }

        if best_match and best_match['confidence'] >= self.confidence_threshold:
            return best_match

        return None

    def _auto_sort_image(self, file_path: str, download_id: Optional[int],
                        person_id: int, confidence: float,
                        encoding: np.ndarray, location: Tuple) -> Dict:
        """Move image to person's directory"""

        # Get person info
        with sqlite3.connect(self.db_path) as conn:
            cursor = conn.execute(
                "SELECT name, directory FROM face_recognition_people WHERE id = ?",
                (person_id,)
            )
            row = cursor.fetchone()
            if not row:
                return {'status': 'error', 'message': 'Person not found'}

            person_name, person_dir = row

        # Create person directory
        target_dir = os.path.join(self.base_directory, person_dir)
        os.makedirs(target_dir, exist_ok=True)

        # Move file
        filename = os.path.basename(file_path)
        target_path = os.path.join(target_dir, filename)

        try:
            shutil.move(file_path, target_path)
            logger.info(f"Auto-sorted {filename} to {person_name} (confidence: {confidence:.2f})")

            # Record in history
            with sqlite3.connect(self.db_path) as conn:
                conn.execute("""
                    INSERT INTO face_recognition_history
                    (download_id, file_path, person_id, confidence, action, processed_at)
                    VALUES (?, ?, ?, ?, 'auto_sorted', ?)
                """, (download_id, target_path, person_id, confidence, datetime.now().isoformat()))
                conn.commit()

            return {
                'status': 'success',
                'action': 'auto_sorted',
                'person_id': person_id,
                'person_name': person_name,
                'confidence': confidence,
                'faces_found': 1,
                'new_path': target_path,
                'message': f'Auto-sorted to {person_name}'
            }

        except Exception as e:
            logger.error(f"Error moving file: {e}")
            return {'status': 'error', 'message': str(e)}

    def _queue_for_review(self, file_path: str, download_id: Optional[int],
                          encoding: np.ndarray, location: Tuple,
                          suggested_person_id: Optional[int] = None,
                          confidence: Optional[float] = None) -> Dict:
        """Add image to review queue"""

        # Copy file to review queue
        filename = os.path.basename(file_path)
        queue_filename = f"queue_{datetime.now().strftime('%Y%m%d_%H%M%S')}_{filename}"
        queue_path = os.path.join(self.review_queue_dir, queue_filename)

        try:
            shutil.copy2(file_path, queue_path)

            # Create thumbnail showing face location
            thumbnail_path = self._create_face_thumbnail(queue_path, location)

            # Add to queue database
            with sqlite3.connect(self.db_path) as conn:
                conn.execute("""
                    INSERT INTO face_recognition_queue
                    (download_id, file_path, thumbnail_path, face_encoding,
                     face_location, confidence, suggested_person_id, status, created_at)
                    VALUES (?, ?, ?, ?, ?, ?, ?, 'pending', ?)
                """, (
                    download_id, queue_path, thumbnail_path,
                    pickle.dumps([encoding]), json.dumps(location),
                    confidence, suggested_person_id, datetime.now().isoformat()
                ))
                conn.commit()

            logger.info(f"Queued {filename} for review (confidence: {confidence:.2f if confidence else 0})")

            return {
                'status': 'success',
                'action': 'queued',
                'suggested_person_id': suggested_person_id,
                'confidence': confidence,
                'faces_found': 1,
                'queue_path': queue_path,
                'message': 'Queued for manual review'
            }

        except Exception as e:
            logger.error(f"Error queueing file: {e}")
            return {'status': 'error', 'message': str(e)}

    def _handle_multiple_faces(self, file_path: str, download_id: Optional[int],
                               encodings: List, locations: List) -> Dict:
        """Handle images with multiple faces"""

        # For now, queue all multiple-face images for review
        filename = os.path.basename(file_path)
        queue_filename = f"multiple_{datetime.now().strftime('%Y%m%d_%H%M%S')}_{filename}"
        queue_path = os.path.join(self.review_queue_dir, queue_filename)

        try:
            shutil.copy2(file_path, queue_path)

            # Store all face encodings
            with sqlite3.connect(self.db_path) as conn:
                conn.execute("""
                    INSERT INTO face_recognition_queue
                    (download_id, file_path, face_encoding, face_location, status, created_at)
                    VALUES (?, ?, ?, ?, 'pending_multiple', ?)
                """, (
                    download_id, queue_path,
                    pickle.dumps(encodings), json.dumps(locations),
                    datetime.now().isoformat()
                ))
                conn.commit()

            logger.info(f"Queued {filename} (multiple faces: {len(encodings)})")

            return {
                'status': 'success',
                'action': 'queued',
                'faces_found': len(encodings),
                'queue_path': queue_path,
                'message': f'Queued - {len(encodings)} faces detected'
            }

        except Exception as e:
            logger.error(f"Error queueing multiple face file: {e}")
            return {'status': 'error', 'message': str(e)}

    def _create_face_thumbnail(self, image_path: str, location: Tuple) -> str:
        """Create thumbnail with face highlighted"""
        try:
            from PIL import Image, ImageDraw

            img = Image.open(image_path)
            draw = ImageDraw.Draw(img)

            # Draw rectangle around face
            top, right, bottom, left = location
            draw.rectangle(((left, top), (right, bottom)), outline="red", width=3)

            # Save thumbnail
            thumbnail_path = image_path.replace('.jpg', '_thumb.jpg')
            img.thumbnail((300, 300))
            img.save(thumbnail_path)

            return thumbnail_path

        except Exception as e:
            logger.error(f"Error creating thumbnail: {e}")
            return None

    # Additional methods for managing people, review queue, etc...
    # (add_person, train_from_images, review_queue_item, etc.)
```

---

### 3. Integration Points

#### A. Post-Download Hook

Modify existing download completion to trigger face recognition:

```python
# In modules/download_manager.py or relevant module

def on_download_complete(file_path: str, download_id: int):
    """Called when download completes"""

    # Existing post-download tasks
    update_database(download_id)
    send_notification(download_id)

    # NEW: Face recognition processing
    if config.get('face_recognition', {}).get('enabled', False):
        from modules.face_recognition_manager import FaceRecognitionManager

        face_mgr = FaceRecognitionManager(db_path, config)
        result = face_mgr.process_image(file_path, download_id)

        logger.info(f"Face recognition result: {result}")
```

#### B. Configuration

Add to `config.json`:

```json
{
  "face_recognition": {
    "enabled": false,
    "confidence_threshold": 0.6,
    "auto_sort_threshold": 0.5,
    "base_directory": "/mnt/storage/Downloads/faces",
    "process_existing": false,
    "async_processing": true,
    "batch_size": 10
  }
}
```

#### C. Web UI Integration

New pages needed:
1. **Face Recognition Dashboard** - Overview, stats, enable/disable
2. **People Management** - Add/edit/remove people, train faces
3. **Review Queue** - Manually identify unknown faces
4. **History** - View auto-sort history, statistics

---

## 🚀 Implementation Phases

### Phase 1: Core Foundation (Week 1)
- [ ] Install face_recognition library
- [ ] Create database schema
- [ ] Build FaceRecognitionManager class
- [ ] Basic face detection and encoding
- [ ] Test with sample images

### Phase 2: People Management (Week 2)
- [ ] Add person to database
- [ ] Train from sample images
- [ ] Store face encodings
- [ ] Load known faces into memory
- [ ] Test matching algorithm

### Phase 3: Auto-Sorting (Week 3)
- [ ] Integrate with download completion hook
- [ ] Implement auto-sort logic
- [ ] Create person directories
- [ ] Move files automatically
- [ ] Log history

### Phase 4: Review Queue (Week 4)
- [ ] Queue unknown faces
- [ ] Create thumbnails
- [ ] Build web UI for review
- [ ] Manual identification workflow
- [ ] Learn from manual reviews

### Phase 5: Web Interface (Week 5-6)
- [ ] Dashboard page
- [ ] People management page
- [ ] Review queue page
- [ ] Statistics and history
- [ ] Settings configuration

### Phase 6: Optimization & Polish (Week 7-8)
- [ ] Async/background processing
- [ ] Batch processing for existing files
- [ ] Performance optimization
- [ ] Error handling and logging
- [ ] Documentation and testing

---

## 📊 API Endpoints (New)

```python
# Face Recognition Management
GET    /api/face-recognition/status
POST   /api/face-recognition/enable
POST   /api/face-recognition/disable

# People Management
GET    /api/face-recognition/people
POST   /api/face-recognition/people          # Add new person
PUT    /api/face-recognition/people/{id}     # Update person
DELETE /api/face-recognition/people/{id}     # Remove person
POST   /api/face-recognition/people/{id}/train  # Train with new images

# Review Queue
GET    /api/face-recognition/queue           # Get pending items
GET    /api/face-recognition/queue/{id}      # Get specific item
POST   /api/face-recognition/queue/{id}/identify  # Manual identification
POST   /api/face-recognition/queue/{id}/skip      # Skip this image
DELETE /api/face-recognition/queue/{id}      # Remove from queue

# History & Stats
GET    /api/face-recognition/history
GET    /api/face-recognition/stats

# Batch Processing
POST   /api/face-recognition/process-existing  # Process old downloads
GET    /api/face-recognition/process-status    # Check batch progress
```

---

## 🎨 Web UI Mockup

### Dashboard Page

```
┌─────────────────────────────────────────────┐
│ Face Recognition Dashboard                  │
├─────────────────────────────────────────────┤
│                                             │
│ Status: [✓ Enabled] [⚙️ Configure]         │
│                                             │
│ ┌───────────────────────────────────────┐  │
│ │ Statistics                            │  │
│ │                                       │  │
│ │ Known People: 12                      │  │
│ │ Auto-Sorted Today: 45                 │  │
│ │ Review Queue: 8 pending               │  │
│ │ Success Rate: 94.2%                   │  │
│ └───────────────────────────────────────┘  │
│                                             │
│ ┌───────────────────────────────────────┐  │
│ │ Recent Activity                       │  │
│ │                                       │  │
│ │ • 14:23 - Auto-sorted to "John"       │  │
│ │ • 14:20 - Queued unknown face         │  │
│ │ • 14:18 - Auto-sorted to "Sarah"      │  │
│ └───────────────────────────────────────┘  │
│                                             │
│ [Manage People] [Review Queue] [Settings]  │
└─────────────────────────────────────────────┘
```

### People Management Page

```
┌─────────────────────────────────────────────┐
│ People Management                           │
├─────────────────────────────────────────────┤
│                                             │
│ [+ Add New Person]                          │
│                                             │
│ ┌───────────────────────────────────────┐  │
│ │ 👤 John Doe                           │  │
│ │ Directory: john_doe/                  │  │
│ │ Face Samples: 25                      │  │
│ │ Images Sorted: 142                    │  │
│ │ [Edit] [Train More] [Delete]          │  │
│ └───────────────────────────────────────┘  │
│                                             │
│ ┌───────────────────────────────────────┐  │
│ │ 👤 Sarah Smith                        │  │
│ │ Directory: sarah_smith/               │  │
│ │ Face Samples: 18                      │  │
│ │ Images Sorted: 89                     │  │
│ │ [Edit] [Train More] [Delete]          │  │
│ └───────────────────────────────────────┘  │
└─────────────────────────────────────────────┘
```

### Review Queue Page

```
┌─────────────────────────────────────────────┐
│ Review Queue (8 pending)                    │
├─────────────────────────────────────────────┤
│                                             │
│ ┌───────────────────────────────────────┐  │
│ │ [Image Thumbnail]                     │  │
│ │                                       │  │
│ │ Confidence: 45% (Low)                 │  │
│ │ Suggested: John Doe                   │  │
│ │                                       │  │
│ │ This is: [Select Person ▼]           │  │
│ │                                       │  │
│ │ [✓ Confirm] [Skip] [New Person]      │  │
│ └───────────────────────────────────────┘  │
│                                             │
│ [◄ Previous] [Next ►]                       │
└─────────────────────────────────────────────┘
```

---

## 🔒 Privacy & Security

1. **Local Processing Only** - No cloud APIs, all processing local
2. **Encrypted Storage** - Face encodings stored securely
3. **User Control** - Easy enable/disable, delete data anytime
4. **Access Control** - Face recognition UI requires authentication
5. **Audit Trail** - All auto-sort actions logged with confidence scores

---

## ⚡ Performance Considerations

### Processing Speed
- Face detection: ~0.5-1 sec per image
- Face recognition: ~0.1 sec per comparison
- Total per image: 1-3 seconds

### Optimization Strategies
1. **Async Processing** - Process in background, don't block downloads
2. **Batch Processing** - Process multiple images in parallel
3. **Caching** - Keep known face encodings in memory
4. **Smart Queueing** - Process high-priority images first
5. **CPU vs GPU** - Optional GPU acceleration for faster processing

---

## 📝 Configuration Example

```json
{
  "face_recognition": {
    "enabled": true,
    "confidence_threshold": 0.6,
    "auto_sort_threshold": 0.5,
    "base_directory": "/mnt/storage/Downloads/faces",
    "review_queue_dir": "/mnt/storage/Downloads/faces/review_queue",
    "process_existing": false,
    "async_processing": true,
    "batch_size": 10,
    "max_faces_per_image": 5,
    "create_thumbnails": true,
    "notify_on_queue": true,
    "gpu_acceleration": false
  }
}
```

---

## 🧪 Testing Plan

### Unit Tests
- Face detection accuracy
- Face matching accuracy
- Database operations
- File operations

### Integration Tests
- End-to-end download → face recognition → sort
- Review queue workflow
- Training new people

### Performance Tests
- Processing speed benchmarks
- Memory usage monitoring
- Concurrent processing

---

## 📈 Success Metrics

- **Accuracy**: >90% correct auto-sort rate
- **Performance**: <3 seconds per image processing
- **Usability**: <5 minutes to add and train new person
- **Review Queue**: <10% of images requiring manual review
- **Stability**: No crashes or errors during processing

---

## 🚀 Getting Started (Once Implemented)

### 1. Enable Face Recognition
```bash
# Install dependencies
pip3 install face_recognition pillow

# Enable in config
# Set "face_recognition.enabled": true
```

### 2. Add Your First Person
```python
# Via Web UI or CLI
# 1. Create person
# 2. Upload 5-10 sample images
# 3. Train face recognition
```

### 3. Process Images
```bash
# Automatic: New downloads are processed automatically
# Manual: Process existing downloads
curl -X POST http://localhost:8000/api/face-recognition/process-existing
```

### 4. Review Unknown Faces
- Open Review Queue in web UI
- Identify unknown faces
- System learns from your identifications

---

## 🔮 Future Enhancements

### v2 Features
- **Multiple face handling** - Split images with multiple people
- **Age progression** - Recognize people across different ages
- **Group detection** - Automatically create "group" folders
- **Emotion detection** - Filter by happy/sad expressions
- **Quality scoring** - Auto-select best photos of each person
- **Duplicate detection** - Find similar poses/angles

### v3 Features
- **Video support** - Extract faces from videos
- **Live camera** - Real-time face recognition
- **Object detection** - Sort by objects/scenes too
- **Tag suggestions** - AI-powered photo tagging
- **Smart albums** - Auto-generate albums by person/event

---

## 📚 Resources

### Libraries
- [face_recognition](https://github.com/ageitgey/face_recognition) - Main library
- [dlib](http://dlib.net/) - Face detection engine
- [OpenCV](https://opencv.org/) - Image processing

### Documentation
- [Face Recognition Tutorial](https://www.pyimagesearch.com/2018/06/18/face-recognition-with-opencv-python-and-deep-learning/)
- [DeepFace GitHub](https://github.com/serengil/deepface)

---

**Status**: Ready for implementation
**Next Step**: Phase 1 - Install dependencies and build core foundation
**Questions**: See [IMPLEMENTATION_GUIDE.md] for step-by-step instructions

---

**Last Updated**: 2025-10-31
