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Image Forgery Detection under Generative and Composited Background Replacement: A Benchmark with Processing-Matched Controls

AspireAI community · arXiv
BG-REAL is a benchmark of 25,624 images built from 2,485 Open Images photographs, where each recipient image is edited by donor compositing, learned harmonization, generative background inpainting, foreground-conditioned relighting or local background edits, and is paired with authentic controls that share the processing but not the semantic edit. Three generators including FLUX.1 Fill, along with scene categories and subject classes, are held out. The authors report that seven detectors published between 2022 and 2026 reach zero-shot AUROCs of at most 0.745 with no useful operating point, because manipulation localisers mark the preserved subject instead of the replaced background and an AI-generated-image detector flags most authentic images passed through a diffusion autoencoder. After fine-tuning the strongest detectors reach an AUROC of about 0.95, while re-implemented background-forgery detectors stay below 0.80. The data are released. This is a v3 revision; v2 was already a substantial rewrite and the title changed from the earlier BG-REAL framing.
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One distance function matched sparse-autoencoder features across layers and compressed feature circuits into supernodes
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