The Research And Application Of A Digital Watermarking Algorithm Based On Scrambling And Single-value Decomposition

With the popularization of Internet and the development of multimedia technique, the digital media has become a more fast and convenient way for information communication. But at the same time, this also leads to serious problem regarding IPR protection. An effective method must be used to provide copyright protection for digital media. Digital watermarking technology has drawn extensive attention in recent years.The theory is an important research of the digital watermark in practical value. The paper introduces the research current situation of the digital watermark and vision of future, generality expound the fact digital essential feature, classification and basic frame and system model, algorithm of watermark, attack issue and performance appraisement. Then this paper presents a digital watermarking arithmetic that combines image scrambling and single-value decomposition of matrix at reducing dimension of image. It is an algorithm based on space domain and transform domain. In this algorithm, the first step is to encrypt source image and watermark image by image scrambling technology. Then the encrypted source image will be reduced image dimension, and decomposing the new image in single-value, the watermark information is embedded into the diagonal matrix. At the end, the difference value of the diagonal matrix has been changed and would be embed the space domain of source image. There are two innovations in this arithmetic.(1) Encrypting both source image and watermark image. This help to enhance the key space under ensuring arithmetic efficiency, so the security of watermark is improved, enhanced the safety and validity.(2) Watermark information has been embedded the single-value decomposition of low dimension image. This algorithm has very excellent robust because of the good algebra characteristic of single-value decomposition.The experiment shows that the arithmetic is very robust to traditional image processing such as noise, compression, filtering, histogram processing and parallel moving, and the arithmetic has fairish resistance to rotation and cut. What's more, this algorithm is a unilateral and nonreversible watermarking arithmetic, so it can provide genuine copyright protection to digital image.