AI-Generated Image Detectors Overrely on Global Artifacts: Evidence from Inpainting Exchange
Current AI-generated image detectors exhibit insufficient reliability in identifying localized inpainting, as they overly rely on global spectral artifacts introduced by VAE reconstruction rather than on genuine synthetic content. To address this, this work proposes the Inpainting Exchange (INP-X) operation, which preserves the inpainted region’s content while restoring original pixels in non-edited areas, thereby systematically revealing— for the first time—the detectors’ dependence on global artifacts. A newly constructed 90K test set based on INP-X demonstrates a significant performance drop in state-of-the-art detectors (e.g., from 91% to 55% accuracy), approaching random guessing. Conversely, models trained on this dataset show markedly improved generalization and localization capabilities, advancing the development of content-aware detection methodologies.