With the rapid development of wireless communication systems, transmission of digital multimedia has become widely spread. This brings with itself the issue of copyright protection for digital work. Digital watermarking is the process of embedding data inside a host image such that it does not degrade the perceptual quality of the image. In recent years, there have been many approaches to introduce different watermarking algorithms for the purposes of copyright protection, broadcast monitoring and covert communication. In this paper, a new transform based watermarking algorithm for digital images is introduced. This method uses the Singular Value Decomposition to obtain the eigenimages of a given image which are known to be the best orthogonal basis that can express that image in a least squares sense. The watermark is embedded by changing the strength of the singular values. The strength of the watermark is determined based on the entropy of the eigenimages to ensure robustness and imperceptibility at the simultaneously. A corresponding watermark detection and extraction algorithm is proposed. The performance of the algorithm under different types of attacks that a digital image can go through during transmission is illustrated through an example.
Selin Aviyente, Selin Aviyente,
"An information theoretic approach to digital image watermarking", Proc. SPIE 5150, Visual Communications and Image Processing 2003, (23 June 2003); doi: 10.1117/12.502886; https://doi.org/10.1117/12.502886