An Introduction in Digital Watermarking: Applications, Principles, and Problems
Tino Jahnke (University of Cooperative Education, Heidenheim, Germany) and Juergen Seitz (University of Cooperative Education, Heidenheim, Germany)
Copyright: © 2008
In order to solve intellectual property problems of the digital age, two basic procedures are used: “Buy and drop,” linked to the destruction of various peer-to-peer solutions and “subpoena and fear,” as the creation of non-natural social fear by specific legislations. Although customers around the world are willing to buy digital products over networks, the industry is still using conventional procedures to push such a decisive customer impulse back into existing and conventional markets. Digital watermarking is described as a possibility to interface and close the gap between copyright and digital distribution. It is based on steganographic techniques and enables useful right protection mechanisms. Digital watermarks are mostly inserted as a plain bit sample or a transformed digital signal into the source data using a key based embedding algorithm and a pseudo-noise pattern. The embedded information is hidden in low-value bits or least significant bits of picture pixels, frequency or other value domains, and linked inseparably with the source of the data structure. For the optimal application of watermarking technology a trade-off has to be made between competing criteria like robustness, non-perceptibility, non-delectability, and security. Most watermarking algorithms are resistant against selected and application-specific attacks. Therefore, even friendly attacks in the form of usual file and data modifications can destroy easily the watermark or falsify it. This chapter gives an overview in watermarking technologies, classification, methodology, applications and problems.