About Face Recognition
Learn about face recognition technology, how it works, and common metrics used to evaluate performance.
What is Face Recognition?
Face recognition is a biometric technology that identifies or verifies a person's identity using their facial features. Modern systems typically extract facial features, convert them into mathematical representations called embeddings, and compare these embeddings to identify matches.
Key Terms and Metrics
| Term | Description |
|---|---|
| Face Embedding | A numerical vector (typically 128-512 dimensions) that represents a face's unique features |
| Similarity Score | A measure of how similar two face embeddings are (0-1, where 1 means identical) |
| Threshold | The minimum similarity score required to consider two faces as matching |
| FAR (False Accept Rate) | The rate at which the system incorrectly accepts an unauthorized user |
| FRR (False Reject Rate) | The rate at which the system incorrectly rejects an authorized user |
| EER (Equal Error Rate) | The point where FAR equals FRR, used as a single metric to evaluate system performance |
| Facial Landmarks | Specific points on a face (eyes, nose, etc.) used for alignment and feature extraction |
Common Applications
- Access Control: Building access, device unlocking
- Security: Surveillance, law enforcement
- Authentication: Banking, identity verification
- User Experience: Photo organization, social media tagging
How Face Recognition Works
- Face Detection: Locate faces in an image
- Face Alignment: Normalize position, size, and pose
- Feature Extraction: Convert facial features to numerical representation
- Matching: Compare embeddings to determine similarity
- Decision: Apply threshold to decide if faces match
