Research On Digital Watermarking Based On DCT Domain And Image Scrambling

The rapid development of digital technology and the popularization of the Internet have brought great convenience to people's work and life.However,by the information openness and sharing,some malicious behavior such as copyright infringement,information tampering,etc.,seriously damage the interests of the creators and users of digital works.Therefore,the protection of digital media has become a hot issue in the world.In this paper,a robust watermarking algorithm based on DCT domain is analyzed by studying the Discrete Cosine Transform and Human Visual System.According to the texture feature and edge sensitive characteristics of the host image,the sub blocks are sorted according to the edge information,and the sub blocks of the same edge information are sorted according to the variance.The block which on front is more suitable for watermark embedding,In order to adapt to the embedded method,this paper constructs a random number sequence generator to determine the embedding position and the change range.According to the human vision system,the block which in the front of the sequence can be modified more,the block which in the end of the sequence can be modified little.The watermark information is embedded in the intermediate frequency of the DCT transform domain and the robustness and the imperceptibility of the algorithm are proved by a large number of experiments.At the same time,the influence of the embedding strength and the embedding capacity of the algorithm is analyzed.Image scrambling transformation can encrypt images and eliminate the correlation of the internal information of the image.In the design of digital watermarking system,a good image scrambling transformation can disperse the distribution of the error bits in the host image,so as to improve the robustness of the digital watermarking system.This paper uses a block mapping?Arnold position scrambling and Logistic pixel scrambling,which is used as the watermark image preprocessing method.The scrambling watermark is used in the algorithm,The simulation results show that the watermarking system is feasible.