July 2026

Conference Paper

SimLBR: Learning to Detect Fake Images by Learning to Detect Real Images

By:
Dhakal, Aayush; Khanal, Subash; Sastry, Srikumar; Arndt, Jacob W; Ambrozio Dias, Philipe ; Lunga, Wadzanai D; Jacobs, Nathan
Page Number:
35472-35482
Book Title:
Proceedings of the 2026 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)
Publication Date:
July 6, 2026
Publisher Location:
IEEE, New Jersey, United States of America
Conference Name:
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)
Conference Location:
Denver, Colorado, United States of America
Conference Sponsor:
IEEE

Abstract

The rapid advancement of generative models has made the detection of AI-generated images a critical challenge for both research and society. Recent works have shown that most state-of-the-art fake image detection methods overfit to their training data and catastrophically fail when evaluated on curated hard test sets with strong distribution shifts. In this work, we argue that it is more principled to learn a tight decision boundary around the real image distribution and treat the fake category as a sink class. To this end, we propose SimLBR, a simple and efficient framework for fake image detection with Latent Blending Regularization (LBR). Our method significantly improves cross-generator generalization, achieving up to +24.85% accuracy and +69.62% recall on the challenging Chameleon benchmark. SimLBR is also highly efficient, training orders of magnitude faster than existing approaches. Furthermore, we emphasize the need for reliability-oriented evaluation in fake image detection, introducing risk-adjusted metrics and worst-case estimates to better assess model robustness. All the code and models are availabe at: https://github.com/mvrl/SimLBR