Document watermarking based on digital holographic principle
This addresses document security for printed materials, but it is incremental as it builds on prior digital image watermarking methods.
The paper tackles the problem of document watermarking by applying digital Fourier hologram principles to printed documents, achieving invisibility, robustness, and non-reproducibility while offering advantages over conventional methods like embossed hologram.
A new method for document watermarking based on the digital Fourier hologram is proposed. It applies the methods of digital image watermarking based on holographic principle presented previously in several papers into printed documents. Experimental results show that the proposed method can not only meet the demand on invisibility, robustness and non-reproducibility of the document watermark, and but also has other advantages compared with the conventional methods for document securities such as embossed hologram, Lippmann photograph and halftone modulation.