Concepts

Reference pages on the science of biometric recognition. Each page covers one modality or one cross-cutting topic, and links into the others where the science overlaps.

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Biometric modalities

Concept	Modality	Summary
Facial Recognition Systems	Face	Face detection, alignment, embedding, and verification / identification pipelines
Iris Recognition	Iris	Iris segmentation, normalization, encoding (IrisCode and deep), and matching
Fingerprint Recognition	Fingerprint	Minutiae extraction, ridge analysis, fixed-length embeddings, latent matching
Palm Recognition	Palm	Palmprint and palm-vein recognition; contactless retail payments
Gait Analysis	Gait	Silhouette- and skeleton-based gait recognition at a distance
Voice Biometrics	Voice	Speaker verification via deep embeddings (ECAPA-TDNN, WavLM)

Systems and architecture

Concept	Scope	Summary
Multimodal Biometrics	Multi	Score-, feature-, and decision-level fusion of multiple modalities
Anti-Spoofing Techniques	Cross-modal	Presentation attack detection across modalities
Deep Learning Architectures for Biometrics	Cross-modal	CNNs, ViTs, GCNs, loss functions, and training strategies
Transformer Architectures for Biometrics	Cross-modal	ViTs, cross-attention fusion, self-supervised pre-training

Quality, ethics, and deployment

Concept	Scope	Summary
Bias and Fairness in Biometrics	Cross-modal	Demographic disparities, measurement frameworks, mitigation
Privacy-Preserving Biometrics	Cross-modal	Template protection, HE, federated learning, cancelable biometrics
Biometric Image Quality	Cross-modal	Quality prediction, NFIQ, FIQA, quality-aware training
Biometric Datasets and Benchmarks	Cross-modal	Major datasets, NIST evaluations, competitions
Real-World Biometric Deployments	Cross-modal	Border control, mobile, payments, national ID, law enforcement