Robust AI-Generated Face Detection with Imbalanced Data
Yamini Sri Krubha, Aryana Hou, Braden Vester, Web Walker, Xin Wang, Li Lin, Shu Hu
TL;DR
This work tackles robust detection of AI-generated face media in the presence of severe data imbalance and evolving generation techniques. It introduces a CLIP-based detection framework that fuses a frozen CLIP ViT-L/14 encoder with a 3-layer MLP, enhanced by latent feature augmentation and a learning objective that combines CVaR loss and AUC loss, optimized via sharpness-aware minimization. Empirical results on the DFWild-Cup benchmark show state-of-the-art performance across AUC, accuracy, F1, and EER, with ablations confirming the value of CVaR for imbalanced data and the effectiveness of a compact MLP. The approach offers robust cross-domain detection with strong generalization to unseen generative models, making it well-suited for real-world deployment where data imbalance and model evolution are persistent concerns.
Abstract
Deepfakes, created using advanced AI techniques such as Variational Autoencoder and Generative Adversarial Networks, have evolved from research and entertainment applications into tools for malicious activities, posing significant threats to digital trust. Current deepfake detection techniques have evolved from CNN-based methods focused on local artifacts to more advanced approaches using vision transformers and multimodal models like CLIP, which capture global anomalies and improve cross-domain generalization. Despite recent progress, state-of-the-art deepfake detectors still face major challenges in handling distribution shifts from emerging generative models and addressing severe class imbalance between authentic and fake samples in deepfake datasets, which limits their robustness and detection accuracy. To address these challenges, we propose a framework that combines dynamic loss reweighting and ranking-based optimization, which achieves superior generalization and performance under imbalanced dataset conditions. The code is available at https://github.com/Purdue-M2/SP_CUP.
