Achieving Resolution-Agnostic DNN-based Image Watermarking: A Novel Perspective of Implicit Neural Representation

Yuchen Wang, Xingyu Zhu, Guanhui Ye, Shiyao Zhang, Xuetao Wei

Abstract: DNN-based watermarking methods are rapidly developing and delivering impressive performances. Recent advances achieve resolution-agnostic image watermarking by reducing the variant resolution watermarking problem to a fixed resolution watermarking problem. However, such a reduction process can potentially introduce artifacts and low robustness. To address this issue, we propose the first, to the best of our knowledge, Resolution-Agnostic Image WaterMarking (RAIMark) framework by watermarking the implicit neural representation (INR) of image. Unlike previous methods, our method does not rely on the previous reduction process by directly watermarking the continuous signal instead of image pixels, thus achieving resolution-agnostic watermarking. Precisely, given an arbitrary-resolution image, we fit an INR for the target image. As a continuous signal, such an INR can be sampled to obtain images with variant resolutions. Then, we quickly fine-tune the fitted INR to get a watermarked INR conditioned on a binary secret message. A pre-trained watermark decoder extracts the hidden message from any sampled images with arbitrary resolutions. By directly watermarking INR, we achieve resolution-agnostic watermarking with increased robustness. Extensive experiments show that our method outperforms previous methods with significant improvements: averagely improved bit accuracy by 7\%$\sim$29\%. Notably, we observe that previous methods are vulnerable to at least one watermarking attack (e.g. JPEG, crop, resize), while ours are robust against all watermarking attacks.

Primary Subject Area: [Experience] Multimedia Applications

Relevance To Conference: Our work focuses on solving the problem of copyright protection of images in multimedia content. We propose a novel resolution-agnostic watermarking framework based on Implicit Neural Representation (INR) to solve the limitation of previous work. We only need to watermark INR to get images of different sizes by sampling, which saves computational overhead. This approach also improves robustness and invisibility considerably compared to previous schemes. INR can express various multimedia resources, and our watermarking scheme provides a novel perspective for subsequent resolution-agnostic watermarking frameworks.

Submission Number: 2702