Fairness Under Cover: Evaluating the Impact of Occlusions on Demographic Bias in Facial Recognition
Rafael M. Mamede, Pedro C. Neto, Ana F. Sequeira
TL;DR
The paper addresses fairness in occluded face recognition by introducing the Face Occlusion Impact Ratio (FOIR) to quantify how occluded regions interact with model reliance on different demographic groups. It analyzes occluded (RFW1, RFW4) and unoccluded (RFW0) conditions using two architectures (ResNet34, ResNet50) trained with ElasticArcFace on two datasets (BUPT-Balanced, BUPT-GlobalFace) and evaluates a suite of group fairness metrics. The results show that occlusions worsen overall performance and amplify demographic disparities, with African individuals typically experiencing larger accuracy drops, and that some ratio-based metrics may falsely appear more fair due to higher overall error; FOIR and pixel-attribution analyses reveal ethnicity-specific occlusion effects in false non-match cases. The work highlights the need to assess fairness under realistic occlusions and provides FOIR as a practical tool for diagnosing and mitigating bias in occluded face recognition.
Abstract
This study investigates the effects of occlusions on the fairness of face recognition systems, particularly focusing on demographic biases. Using the Racial Faces in the Wild (RFW) dataset and synthetically added realistic occlusions, we evaluate their effect on the performance of face recognition models trained on the BUPT-Balanced and BUPT-GlobalFace datasets. We note increases in the dispersion of FMR, FNMR, and accuracy alongside decreases in fairness according to Equilized Odds, Demographic Parity, STD of Accuracy, and Fairness Discrepancy Rate. Additionally, we utilize a pixel attribution method to understand the importance of occlusions in model predictions, proposing a new metric, Face Occlusion Impact Ratio (FOIR), that quantifies the extent to which occlusions affect model performance across different demographic groups. Our results indicate that occlusions exacerbate existing demographic biases, with models placing higher importance on occlusions in an unequal fashion, particularly affecting African individuals more severely.
