Generalized Image-Based Deepfake Detection Through Foundation Model Adaptation

Abstract

With the rapid advancement of image synthesis and manipulation techniques from Generative Adversarial Networks (GANs) to Diffusion Models (DMs), the generated images, often referred to as Deepfakes, have been indistinguishable from genuine images by human and thus raised the public concerns about potential risks of malicious exploitation such as dissemination of misinformation. However, it remains an open and challenging task to detect Deepfakes, especially to generalize to novel and unseen generation methods. To address this issue, we propose a novel generalized Deepfake detector for diverse AI-generated images. Our proposed detector, a side-network-based adapter, leverages the rich prior encoded in the multi-layer features of the image encoder from Contrastive Language Image Pre-training (CLIP) for effective feature aggregation and detection. In addition, we also introduce the novel Diversely GENerated image dataset (DiGEN), which encompasses the collected real images and the synthetic ones generated from versatile GANs to the latest DMs, to facilitate better model training and evaluation. The dataset well complements the existing ones and contains sixteen different generative models in total over three distinct scenarios. Through extensive experiments, the results demonstrate that our approach effectively generalizes to unseen Deepfakes, significantly surpassing previous state-of-the-art methods. Our code and dataset are available at https://github.com/aiiu-lab/AdaptCLIP.