When AUC Misleads: Polarization-Aware Evaluation of Deepfake Detectors under Domain Shift

· Source: Computer Vision and Pattern Recognition · Field: Technology & Digital — Artificial Intelligence & Machine Learning, Computer Vision & Pattern Recognition · Depth: Expert, quick

Summary

A new metric, Cross-dataset AUC (Cross-AUC), is introduced to more realistically evaluate deepfake detectors, addressing limitations of traditional Area Under the ROC Curve (AUC) methods. Current AUC evaluations, measured separately across multiple datasets, fail to capture real-world scenarios involving mixed data sources and diverse artifact types. Cross-AUC averages per-domain AUCs and incorporates a measure of prediction polarization, quantified by the Wasserstein Distance between class score distributions, to account for robustness to domain shift. This approach not only provides a more accurate assessment of generalization capabilities but also offers interpretability by explaining performance drops. Its practical relevance was demonstrated through experiments on seven benchmark datasets.

Key takeaway

For Machine Learning Engineers developing deepfake detection systems, adopting Cross-dataset AUC (Cross-AUC) is crucial for a realistic evaluation of model generalization. Traditional AUC metrics can obscure performance issues when models encounter diverse, unseen manipulations or mixed data sources. You should integrate Cross-AUC into your evaluation pipeline to accurately assess robustness to domain shift and gain clearer insights into why your detector's performance might degrade in real-world deployments.

Key insights

Cross-AUC offers a polarization-aware evaluation metric for deepfake detectors, improving generalization assessment under domain shift.

Principles

Method

Cross-AUC averages per-domain AUCs with a prediction polarization measure. Polarization extent is quantified by the Wasserstein Distance between class score distributions.

In practice

Topics

Best for: Research Scientist, AI Scientist, Computer Vision Engineer, Machine Learning Engineer

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Editorial summary, takeaway, and curation by AIssential. Original article published by Computer Vision and Pattern Recognition.