Percept-Lens: A Deep Dive into AI-Generated Image Detection

Can a strong general-purpose vision model distinguish real from AI-generated images using only a simple decision rule on frozen representations? Our latest results, to be presented at ECCV2026, show it can.

New image generators keep appearing. A trained AI-generated image detector that works well on familiar images can fail when the generator, prompt, style, or image domain changes. Our benchmark study introduced Percept-Lens, a common evaluation framework for these shifts, and showed how sharply released AI-generated image detectors can degrade beyond familiar data.

That led us to a more basic question. When a detector fails, has its underlying vision model lost the distinction between real and AI-generated images, or is its decision rule failing to recover it?

In our upcoming ECCV paper, we built a new detector by keeping a general-purpose vision model frozen and fitting a simple Gaussian decision rule to its representations. The method models how labeled real and AI-generated images are arranged in the vision model’s feature space, then classifies a new image by the group it most closely resembles.

On the same broad evaluation suite, our detector outperformed the strongest released AI-generated image detector we tested, even though its general purpose vision model had not been trained specifically for this task.

Better vision models will take detection further. Our results show that progress can also come from making better use of the real-versus-generated structure already present in a general-purpose vision model.