CoreMark: Toward Robust and Universal Text Watermarking Technique

TL;DR

CoreMark introduces a robust, language- and font-agnostic text watermarking framework that enhances resistance to various attacks while maintaining visual quality, through a novel CORE embedding paradigm and adaptive embedding strength modulation.

Contribution

The paper presents the CORE embedding paradigm and CoreMark framework, offering improved robustness and generalizability in text watermarking across languages and fonts.

Findings

Outperforms existing methods against screenshot, print-scan, and camera attacks.

Maintains high imperceptibility across diverse languages and fonts.

Demonstrates robustness with adaptive embedding strength modulation.

Abstract

Text watermarking schemes have gained considerable attention in recent years, yet still face critical challenges in achieving simultaneous robustness, generalizability, and imperceptibility. This paper introduces a new embedding paradigm,termed CORE, which comprises several consecutively aligned black pixel segments. Its key innovation lies in its inherent noise resistance during transmission and broad applicability across languages and fonts. Based on the CORE, we present a text watermarking framework named CoreMark. Specifically, CoreMark first dynamically extracts COREs from characters. Then, the characters with stronger robustness are selected according to the lengths of COREs. By modifying the thickness of the CORE, the hidden data is embedded into the selected characters without causing significant visual distortions. Moreover, a general plug-and-play embedding strength modulator is proposed, which can adaptively enhance the robustness for small font sizes by adjusting the embedding strength according to the font size. Experimental evaluation indicates that CoreMark demonstrates outstanding generalizability across multiple languages and fonts. Compared to existing methods, CoreMark achieves significant improvements in resisting screenshot, print-scan, and print camera attacks, while maintaining satisfactory imperceptibility.