Adversarial Shallow Watermarking
Guobiao Li, Lei Tan, Yuliang Xue, Gaozhi Liu, Zhenxing Qian, Sheng Li, Xinpeng Zhang
TL;DR
This paper tackles the robustness gap of learning-based deep watermarking (LDW) against unknown distortions by introducing Adversarial Shallow Watermarking (ASW). ASW fixes a randomly parameterized shallow decoder and performs adversarial embedding to produce watermarked images that reliably trigger the decoder, without training encoders or modeling distortions. Empirical results show ASW delivers competitive performance on known distortions and superior robustness to unknown distortions compared with state-of-the-art LDW methods, while remaining training-free and computationally efficient at extraction. The work provides a new perspective on watermark design by leveraging the distortion-insensitivity of shallow networks, offering practical robustness for real-world media protection.
Abstract
Recent advances in digital watermarking make use of deep neural networks for message embedding and extraction. They typically follow the ``encoder-noise layer-decoder''-based architecture. By deliberately establishing a differentiable noise layer to simulate the distortion of the watermarked signal, they jointly train the deep encoder and decoder to fit the noise layer to guarantee robustness. As a result, they are usually weak against unknown distortions that are not used in their training pipeline. In this paper, we propose a novel watermarking framework to resist unknown distortions, namely Adversarial Shallow Watermarking (ASW). ASW utilizes only a shallow decoder that is randomly parameterized and designed to be insensitive to distortions for watermarking extraction. During the watermark embedding, ASW freezes the shallow decoder and adversarially optimizes a host image until its updated version (i.e., the watermarked image) stably triggers the shallow decoder to output the watermark message. During the watermark extraction, it accurately recovers the message from the watermarked image by leveraging the insensitive nature of the shallow decoder against arbitrary distortions. Our ASW is training-free, encoder-free, and noise layer-free. Experiments indicate that the watermarked images created by ASW have strong robustness against various unknown distortions. Compared to the existing ``encoder-noise layer-decoder'' approaches, ASW achieves comparable results on known distortions and better robustness on unknown distortions.
