The Research Of Robust Watermarking Algorithm Based On Relationship Of DCT Coefficients

With the rapid development of information technology, digital media has been playing an increasingly important role in people's lives. However, digital, information product has dual effects, it provides convenience and faces tough security challenges in the meantime because it is very easy to be modified, reproduced and disseminated illegally. Therefore, with the unique advantages of protecting digital content, digital watermarking technology is attracting increasing attention, and has been studied extensively in recent years.In this paper, the basic concepts and research status of digital watermarking technology are introduced; aim at static image, robust watermarking algorithms based on the relationship of DCT coefficients are focused on. Firstly, advantages and disadvantages of the existed watermarking algorithms based on the relationship of DCT coefficients are analyzed and summarized, the theory of watermarking algorithm based on exchanging two DCT coefficients are analyzed and studied in detail, the general guideline that such algorithms resist JPEG compression should be followed is deduced and proved. Secondly, a novel robust watermarking algorithm which applies the guideline and human visual characteristic is designed. Finally, the algorithm is carried out by a large number of simulation experiments, the results are compared with the related literatures. It is showed that the robust watermarking algorithm proposed by this paper is invisible, robust as well as blind extraction; Experimental results are in accord with the theoretical analysis completely.