Robust Reversible Watermarking With Invisible Distortion Against VAE Watermark Removal

Orthogonal Moment-based Robust Reversible Watermarking (OM-RRW) is crucial for intellectual property protection, providing the dual benefits of robustness and reversibility. However, OM-RRW embeds watermarks into visually sensitive global low-frequency features, which easily leads to ring-like distortions that expose watermark locations, making them vulnerable to removal through image inpainting. To address this issue, this paper makes the first attempt to introduce an innovative strategy to eliminate these visible distortions, thereby overcoming OM-RRW's inherent limitations. The strategy innovates on two fronts: first, it customizes varying embedding step sizes based on the stability differences of moment values to minimize distortion; second, it designs a texture-aware adaptive basis function fine-tuning strategy. This strategy adjusts the representation capability of the basis functions in different regions based on the human eye's sensitivity to various texture areas, helping to avoid visible ring-like distortions. The performance of the proposed method is evaluated using Polar Harmonic Transform (PHT) moments, comprising three moments that exhibit remarkable performance in existing OM-RRW methods. Extensive experiments show that the proposed method can embed 128-bit watermarks with no visible distortions while minimizing the loss of robustness. In addition, this paper finds that OM-RRW demonstrates satisfactory robustness against VAE watermark removal attacks.