Towards Good Generalizations for Diffusion Generated Image Detection Using Multiple Reconstruction Contrastive Learning

A striking proficiency of diffusion models in producing and manipulating images with an unprecedented level of realism has unquestionably elicited concerns. Many methods have been proposed to detect generated images. In particular, recent studies reveal that autoencoder reconstruction error can serve as an effective indicator for distinguishing authentic and synthetic images, since most generative models adopt analogous encoder-decoder operation. However, the reliance on a single autoencoder reconstruction error provides only limited information, which is insufficient for comprehensively capturing discriminative features, resulting in restricted generalization performance. In this paper, we propose Multiple Reconstruction Contrastive Learning (MRCL), which leverages multiple reconstruction residuals to enhance the generalizability of generated image detection. Specifically, MRCL applies Dinov2-ViT with LoRA fine-tuning to extract fine-grained feature representations of origin images and their multiple VAE reconstructions. In addition, a Residual Dense Fusion module is designed to effectively combine multiple VAE reconstruction residuals. Further, a contrastive learning strategy is adopted to guide the distance of origin images and VAE reconstruction representations. Extensive experimental results demonstrate the superior generalization performance of the proposed MRCL.