论文标题
CFL网络:使用对比度学习的图像伪造本地化
CFL-Net: Image Forgery Localization Using Contrastive Learning
论文作者
论文摘要
常规的伪造方法通常依赖于不同的伪造足迹,例如JPEG伪像,边缘不一致,摄像机噪声等,并散开损失来定位受操纵的区域。但是,这些方法的缺点是过度拟合,只关注少数特定的伪造足迹。另一方面,现实生活中的操纵图像是通过各种伪造的操作产生的,因此留下了各种各样的伪造足迹。因此,我们需要一种更通用的图像伪造定位方法,该方法可以在各种伪造条件下运作良好。基础锻造区域定位的一个关键假设是,无论伪造类型如何,每个锻造图像样品中未受损和操纵区域之间的特征分布仍然存在差异。在本文中,我们旨在利用特征分布的差异来帮助图像伪造的定位。具体而言,我们使用对比度损失来学习映射到一个特征空间,在该特征空间中,未击击和操纵区域之间的特征是每个图像都可以完善的。同样,我们的方法具有定位操纵区域的优势,而无需对伪造类型进行任何先验知识或假设。我们证明,我们的工作在三个基准图像操作数据集上优于现有方法。代码可在https://github.com/niloy193/cflnet上找到。
Conventional forgery localizing methods usually rely on different forgery footprints such as JPEG artifacts, edge inconsistency, camera noise, etc., with cross-entropy loss to locate manipulated regions. However, these methods have the disadvantage of over-fitting and focusing on only a few specific forgery footprints. On the other hand, real-life manipulated images are generated via a wide variety of forgery operations and thus, leave behind a wide variety of forgery footprints. Therefore, we need a more general approach for image forgery localization that can work well on a variety of forgery conditions. A key assumption in underlying forged region localization is that there remains a difference of feature distribution between untampered and manipulated regions in each forged image sample, irrespective of the forgery type. In this paper, we aim to leverage this difference of feature distribution to aid in image forgery localization. Specifically, we use contrastive loss to learn mapping into a feature space where the features between untampered and manipulated regions are well-separated for each image. Also, our method has the advantage of localizing manipulated region without requiring any prior knowledge or assumption about the forgery type. We demonstrate that our work outperforms several existing methods on three benchmark image manipulation datasets. Code is available at https://github.com/niloy193/CFLNet.