Digital Watermarking: An Introduction

Abstract

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 nonnatural 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. But digital media, like audio, video, images, and other multimedia documents, can be protected against copyright infringements with invisible, integrated patterns based on steganography and digital watermarking techniques. 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 rights 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 such as robustness, nonperceptibility, nondetectability, and security. Most watermarking algorithms are resistant to selected and application-specific attacks. Therefore, even friendly attacks in the form of usual file and data modifications can easily destroy the watermark or falsify it. This paper gives an overview of watermarking technologies, classification, methodology, application, and problems.