A comprehensive analysis of digital watermarking

Copyright protection of digital contents has become more and more important in accordance with the development of digital technology. As a solution of this predicament, digital watermark technology is drawing attention and various watermarking methods have been presented and studied. Digital watermarking provides protection of intellectual property in the digital world. Just as plagiarism runs rampant in the physical world, unauthorized copying of data whether it be audio, visual, or video exists in the digital world. Digital watermarking attempts to copyright the digital data that is freely available on the World Wide Web to protect owner's rights. As opposed to traditional, printed watermarks, digital watermarks are transparent signatures. They are integrated within digital files as noise, or random information that already exists in the file. Thus, detection and removal of the watermark becomes more difficult. Typically, watermarks are dispersed throughout the entire digital file such that manipulation of one portion of the file does not alter the underlying watermark. However, it is difficult to decide which method is better than others, because the measure for evaluating their performance has not been established yet. Recently, digital contents can be easily accessed by using computer networks and the problem of protecting multimedia information becomes more and more important. To resolve various problems occurring in these upcoming areas and future emerging disciplines, digital watermark technology is now drawing attention as a new method and technique of protecting copyrights for digital data. Digital watermark is realized by embedding information data with an insensible form for human audio/visual systems. It must be difficult for an attacker to remove watermark purposely. In this paper an outline of watermarking and analysis of the various techniques used in the area of image watermarking is presented.