RWN: ROBUST WATERMARKING NETWORK FOR IMAGE CROPPING LOCALIZATION

Image cropping can be maliciously used to manipulate the layout of an image and alter the underlying meaning. Previous image cropping detection schemes only predict whether an image has been cropped, ignoring which part of the image is cropped. This paper presents a novel robust watermarking network for image cropping localization. We train an anti-cropping processor (ACP) that embeds a watermark into a target image. The visually indistinguishable protected image is then posted on the social network instead of the original image. At the recipient's side, ACP extracts the watermark from the attacked image, and we conduct feature matching on the original and extracted watermark to locate the position of the cropping. We further extend our scheme to detect tampering attacks on the attacked image, and a simple yet efficient method (JPEG-Mixup) is proposed that noticeably improves the generalization of JPEG robustness. We demonstrate that our scheme is the first to provide high-accuracy and robust image cropping localization.