Supervised Contrastive Learning for Snapshot Spectral Imaging Face Anti-Spoofing
Chuanbiao Song, Yan Hong, Jun Lan, Huijia Zhu, Weiqiang Wang, Jianfu Zhang
TL;DR
This work tackles face anti-spoofing under snapshot spectral imaging by introducing a re-balanced supervised contrastive learning framework that combines data resampling, intra-class mixup, and a Real-face Oriented Reweighting strategy to reduce identity bias. The method processes multimodal inputs (RGB $\oplus$ 30 spectral channels) with a spectral-weighted, multi-attention backbone and optimizes a dual objective: $\mathcal{L} = \mathcal{L}_{\text{c}} + \lambda_{scl} \cdot \mathcal{L}_{\text{scl}}$ (with $\lambda_{scl}=10$), including Focal Loss and a Supervised Contrastive Loss aided by Cross Batch Memory, using $\tau=0.07$ for temperature. On the HySpeFAS dataset, the approach achieves a record ACER of $0.0000\%$, with APCER and BPCER also at $0\%$, ranking 1st in the CVPR 2024 challenge. The findings demonstrate that aligned contrastive learning, proper resampling, and bias-aware weighting can substantially boost SSI-based FAS performance with practical implications for secure biometric systems.
Abstract
This study reveals a cutting-edge re-balanced contrastive learning strategy aimed at strengthening face anti-spoofing capabilities within facial recognition systems, with a focus on countering the challenges posed by printed photos, and highly realistic silicone or latex masks. Leveraging the HySpeFAS dataset, which benefits from Snapshot Spectral Imaging technology to provide hyperspectral images, our approach harmonizes class-level contrastive learning with data resampling and an innovative real-face oriented reweighting technique. This method effectively mitigates dataset imbalances and reduces identity-related biases. Notably, our strategy achieved an unprecedented 0.0000\% Average Classification Error Rate (ACER) on the HySpeFAS dataset, ranking first at the Chalearn Snapshot Spectral Imaging Face Anti-spoofing Challenge on CVPR 2024.
