Ignored Details in Eyes: Exposing GAN-Generated Faces by Sclera

Tong Zhang, Anjie Peng, Hui Zeng

Abstract: Advances in Generative adversarial networks (GAN) have significantly improved the quality of synthetic facial images, posing threats to many vital areas. Thus, identifying whether a presented facial image is synthesized is of forensic importance. Our fundamental discovery is the lack of capillaries in the sclera of the GAN-generated faces, which is caused by the lack of physical/physiological constraints in the GAN model. Because there are more or fewer capillaries in people’s eyes, one can distinguish real faces from GAN-generated ones by carefully examining the sclera area. Following this idea, we first extract the sclera area from a probe image, then feed it into a residual attention network to distinguish GAN-generated faces from real ones. The proposed method is validated on the Flickr-Faces-HQ and StyleGAN2/StyleGAN3-generated face datasets. Experiments demonstrate that the capillary in the sclera is a very effective feature for identifying GAN-generated faces. Our code is available at: https://github.com/10961020/Deepfake-detector-based-on-blood-vessels.