Research On Multiple Digital Watermarking Algorithm

With the rapid development of computer network technology and communication technology,people can conveniently communicate and transmit information through the Internet.The subsequent issues of security and privacy have become increasingly prominent,and the copyrights of various digital products urgently need to be protected.Digital watermarking technology can successfully protect the copyright of digital product owners and reduce the piracy of digital products in the field of modern information security.Because a single watermark cannot solve the problem of multiple copyrights,and it is difficult to protect the integrity of digital products in the complex Internet environment,multiple watermarks need to be studied.This paper mainly studies the preprocessing of digital watermarking and multiple digital watermarking embedding algorithms.Firstly,a double scrambling algorithm is designed to preprocess digital watermarking images,and then the processed watermarks are embedded into the carrier image to achieve digital rights protection and tampering positioning.The main research contents of this article are as follows:1.The preprocessing of digital watermarking technology is studied.Both Zigzag scrambling algorithm and Logistic mapping scrambling algorithm are selected to change the position of the watermark image pixel to scramble.A kind of double encryption based on adjustable sequence is designed.The scrambling algorithm uses a newly constructed position scrambling method to encrypt the watermark image.The implementation process of the algorithm is simple,and it can completely scramble the outline of the watermark image without complicated calculations and has a high degree of scrambling.It lays a foundation for the watermark preprocessing of multiple digital watermark embedding algorithm.2.A multiple digital watermark embedding algorithm based on the spatial and DCT domains is designed.First,the color carrier image is RGB decomposed,and the three components are divided into block discrete cosine transforms respectively.Then Multiple watermark images were scrambled by zigag-logistic are embedded in the intermediate frequency portion of each component,and blind extraction of watermark information can be achieved.Different attacks are performed on watermarked color carrier images,and the watermark information are extracted by simulation to test the robust performance of the embedding algorithm.3.Based on the YIQ color space,multiple digital watermarks are embedded into the color carrier image.Because the Y component in the color space can separately display the brightness information of the color image,and the watermarks embedded in the Y component has little effect to the other two color components.Firstly using haar wavelet to perform three-layer discrete wavelet decomposition on the Y component of the color carrier image,and embedding two robust watermarks in the LL3 and HL3 layers of the Y component for copyright protection and authentication of digital products.An authentication watermark is embedded in the HL2 layer of the Y component to locate areas where the color carrier image is maliciously tampered with.Then a series of simulation experiments are performed to test.The experimental results show that the algorithm has strong robustness,which not only achieve copyright protection,but also achieve the function of tampering position.