发表机构
School of Computer Science and Technology, Xinjiang University（新疆大学计算机科学与技术学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究针对二维线索在图像操纵定位中失效的问题，利用单目重建获取几何线索，设计几何感知框架GFrame，估计其可靠性并与RGB特征融合跨尺度传播，在有限预算下提升定位性能，证明三维几何可补充二维线索用于IML。
AI 中文摘要
现有图像操纵定位（IML）方法严重依赖二维取证线索，如低级伪像、噪声痕迹和操纵图像中的语义不一致。虽然在许多情况下有效，但当操纵区域与周围环境外观很好融合时，这些线索的区分性会大大降低。在这种情况下，操纵区域可能在局部外观上保持一致，但仍违反周围场景的几何结构。这促使我们超越纯二维证据，将几何推理引入IML。为此，我们利用单目重建获得包括深度和表面法线在内的辅助几何线索。然而，关键挑战在于操纵图像上重建的几何本质上是有噪声的，不能直接使用。我们估计其可靠性并选择性地用于定位。基于此，我们设计了一个几何感知框架（GFrame），将可靠的几何线索与RGB特征融合并跨尺度传播以改善细粒度定位。大量实验表明，该方法在有限预算约束下取得了优异性能。这些结果表明，可靠的三维几何为IML提供了超越传统二维线索的补充取证证据。相关代码将发布。
英文摘要
Existing image manipulation localization (IML) methods rely heavily on 2D forensic cues, such as low-level artifacts, noise traces, and semantic inconsistencies in the manipulated image. While effective in many cases, these cues become much less discriminative when manipulated regions are well blended with their surrounding context in appearance. In such cases, a manipulated region may remain locally appearance-consistent, but still violate the geometric structure of the surrounding scene. This limitation motivates us to go beyond purely 2D evidence and introduce geometric reasoning into IML. To this end, we leverage monocular reconstruction to obtain auxiliary geometric cues, including depth and surface normals. However, a key challenge lies in the fact that reconstructed geometry on manipulated images is inherently noisy and cannot be used naively. Rather than treating depth and normals as direct evidence, we estimate their reliability and exploit them selectively for localization. Based on this principle, we design a geometry-aware framework (GFrame) that fuses reliable geometric cues with RGB features and propagates them across scales to improve fine-grained localization. Extensive experiments show that the proposed method achieves excellent performance under limited budget constraints. These results indicate that reliable 3D geometry provides complementary forensic evidence beyond traditional 2D cues for IML. Related code will be released.
