Design And Implementation Of High Performance And High Capacity Watermarking Algorithms Based On Multiple Transform Domains

As the processing speed of computer continues to increase,computer information networks and related businesses also have shown explosive growth,including the Internet,the Internet of Things,and various information networks.The active development of network technology and multimedia technology in various application fields has greatly stimulated the demand for digital products.However,with the increasing apply of digital products,problems such as illegal copying,distribution,and editing are also emerging in endlessly.Digital watermarking technology is one of effective methods to solve the above problems,and could be effectively applied to hiding the copyright information of digital products.Digital watermarking technology could embed the information that needs to be hidden into the information carrier,so as to achieve identity or information authentication.Based on the research of traditional transform domain watermarking technology,this degree combines optical watermarking technology and artificial intelligence algorithm to design and implement two multi-transform domain watermarking algorithms.The specific research contents of the thesis is as follows:A hybrid image watermarking algorithm based on singular value decomposition(SVD)ghost imaging is designed.Simultaneously,the blended watermarking algorithm with optical watermark image is designed based on 4-level discrete wavelet transform,discrete cosine transform and singular value decomposition.First,the original image is transformed by 4-level two-dimensional wavelet transform to obtain the 4th level sub-band image,and then the DCT algorithm is designed to transform the 4th level sub-band image to obtain the coefficient matrix.Then,the watermark image after encryption is generated into another three matrices by singular value decomposition.Before the watermark image is embedded,the optical watermark image is encrypted by SVD ghost imaging system.The system could generate a secret key,and unauthorized users could not decrypt and reconstruct the original watermark image without this key.Later the encrypted watermark image is generated into another three matrices by singular value decomposition.Afterwards,through the inter-operation of different matrices in the algorithm,the encrypted watermark is embedded into the host image.And the simulation results could verify the effectiveness of the proposed hybrid watermarking algorithm based on multiple transformation domain algorithms and singular value decomposition ghost imaging optical system.An imperceptible image watermarking algorithm based on multiple transforms and singular value decomposition ghost imaging optical system is designed.Before the watermark image is embedded,the watermark image is encrypted by utilizing singular value decomposition ghost imaging system.On other side,the encrypted watermark is embedded into the cover image through multiple transforms,including lifting wavelet transform(LWT),discrete cosine transform,discrete fractional angular transform(DFAT)and singular value decomposition.First,the host image is processed by lifting wavelet transform algorithm and four sub-band images are obtained.Then the low-frequency sub-band image could be decomposed into 8×8small matrices,and each matrix could be treated with DCT.The coefficients generated by them are formed into a matrix,and then the coefficients at the upper left corner of each block are selected to form a new matrix.Then singular value decomposition is performed on the two parts of the image,and the watermark is embedded into the host image through the inter-operation of different matrices.Simulation results validate that the proposed watermark scheme is superior in the aspects of security,robustness and imperceptibility.