An Overview of Watermarking

For those reading this, the rapid rise of the Internet in recent years greatly enhances the availability of media of all forms, but that is not news. This will become even more evident in the field of commercial music records where Napster and other Internet-based delivery systems offer incredible music content, without the consent of all music producers. However, this situation is not unique to the music industry, as photographers, filmmakers, and other content creators have similar problems.

Digital watermarks fall into two broad categories: display and non-display. The idea behind the visible watermark is very simple. It is equivalent to putting a watermark on paper, so it is sometimes said to be a digital seal. Television channels such as BBC provide examples of visible watermarks whose logos are visually superimposed at the corners of the television picture. Meanwhile, the invisible watermark is a far more complex concept. It is most commonly used to identify copyright data such as author, distributor and so on.

Invisible watermarking algorithms have different classifications. The reason behind this is the diversity of the watermarking method. The watermarking method can distinguish between the watermarking main signal (still image, video signal, audio signal, integrated circuit design) and the availability of the original signal (non-blind, semi-blind, blind) during extraction. In addition, they can be categorized based on the domain used for the watermark embedding process, as shown. Watermarking applications are considered as one of the criteria for watermark classification. Figure 2 shows the subcategories based on the watermark application.

Digital watermarking technology was developed to protect the copyright of media signals. Different watermarking schemes have been proposed for multimedia contents (images, video and audio signals). This research aims to provide extensive literature review of multimedia copyright protection. It provides a general review and background on the definition of the watermark, the concept and the main contribution of the field. Information spreads widely throughout the global network. These connected networks allow cross-referencing between databases. With the advent of multimedia, various applications can combine voice, images, and video to interact with a lot of information (eg, e-commerce, distance learning, human-machine interface, etc.).