GenDet: Towards Good Generalizations for AI-Generated Image Detection
Mingjian Zhu, Hanting Chen, Mouxiao Huang, Wei Li, Hailin Hu, Jie Hu, Yunhe Wang
TL;DR
GenDet tackles the challenge of detecting AI-generated images from unseen generators by reframing detection as anomaly-like discrimination between real and fake inputs. It combines an adversarial teacher-student discrepancy-aware learning framework with a generalized feature augmenter, training to minimize real-input discrepancy while maximizing fake-input discrepancy, and to further generalize via adversarial feature augmentation. The approach achieves state-of-the-art results on UniversalFakeDetect and GenImage, including strong performance on unseen generators, degraded-image robustness, and cross-dataset transfer. This yields a practically impactful detector that generalizes beyond known generators and remains resilient under common image distortions.
Abstract
The misuse of AI imagery can have harmful societal effects, prompting the creation of detectors to combat issues like the spread of fake news. Existing methods can effectively detect images generated by seen generators, but it is challenging to detect those generated by unseen generators. They do not concentrate on amplifying the output discrepancy when detectors process real versus fake images. This results in a close output distribution of real and fake samples, increasing classification difficulty in detecting unseen generators. This paper addresses the unseen-generator detection problem by considering this task from the perspective of anomaly detection and proposes an adversarial teacher-student discrepancy-aware framework. Our method encourages smaller output discrepancies between the student and the teacher models for real images while aiming for larger discrepancies for fake images. We employ adversarial learning to train a feature augmenter, which promotes smaller discrepancies between teacher and student networks when the inputs are fake images. Our method has achieved state-of-the-art on public benchmarks, and the visualization results show that a large output discrepancy is maintained when faced with various types of generators.
