Research On Image Information Security Technology Based On NSST Transformation

With the development of multimedia technology,images have become a new information carrier widely used.Although the convenience of images brings a lot of benefits,the tampering and illegal copying of image content also has many negative effects on the security and copyright of image information.Digital image tampering detection and digital image watermarking technology are important means of image information security protection.Compared with the spatial domain algorithm,the transform domain based tampering and watermarking algorithm has better efficiency and robustness.In this paper,an image clone detection algorithm and image watermarking algorithm are proposed respectively.The specific contents are as follows:Based on the NSST transform,and using the fast Walsh Hadamard transform instead of the commonly used discrete cosine transform to extract image features,combined with multi-level jump matching algorithm(MHJ),a clone image based on image block matching is proposed.Blind forensics method.The experimental results show that the algorithm not only effectively maintains a high correct rate,but also can greatly reduce the running time.Based on the theory of Cauchy modeling,we propose a image watermarking algorithm in NSST domain,in which the good balance between robustness and imperceptibility can be well maintained.Firstly,the watermark is embedded into the significant NSST coefficients by using a novel multiplicative method.Then,the watermarked image is geometric corrected by applying the amplitude spectrum of 2D Discrete Fourier Transform(DFT).Next,the Cauchy distribution is utilized to model the NSST coefficients,in which fully employ the sub-band coefficients correlation and RSS method.Finally,the Locally Optimum Detection(LOD)is derived to extract the specific watermark bits based on Cauchy model and Local Most Powerful(LMP)test.In this paper,the Cauchy model is optimized by using the Ranked Set Sampled(RSS)method and the correlation of sub-band coefficients.Meanwhile,the LOD detector is developed using the excellent Cauchy model,which can improve the accuracy of watermark detection.The comparison results show that the proposed algorithm is superior to other algorithms in terms of imperceptibility and robustness.