Research Of Digital Image Watermarking Algorithm Based On Transformation Domain

Our times are described as the Internet age, the information age, thedigital age, even micro-age. The digital information make our daily livestremendously change. Our country has invested roads, railways, power gridsand other infrastructure, while the broadband Internet has also increasedinvestment. When people get digital information any where, informationsecurity is facing a great threat and attention to the copyright protection ofdigital products is widely received. Copyright protection needs the constraintsof the laws and regulations and requires researchers to improve anti-attackcapability of digital products technically. Digital watermarking technology is acopyright information hidden technology to protect copyright of digital products,which is a branch of information hiding technology to make up for the lack oftraditional cryptographic techniques. It made important role in the field ofcopyright protection of digital products.This paper describes digital watermarking’s main characteristics, model,the typical algorithm and evaluation standards, and focus on research of digitalimage watermarking algorithm based on transform domain, involving DCTdomain,DWT domain and popular compressed sensing theory. This paperexplains each algorithm from the basic theory, algorithm description androbustness test. On the basis of access to large amounts of literature, on the one hand this paper improve the existing classical algorithm, on the other handit proposes a new watermarking algorithm for digital image.This paper Reproduced digital watermarking algorithm based on classicblock DCT. The original image is divided into sub-blocks and DCT transformthem, then watermark image is divided into the appropriate number of imageblocks and take advantage of the additive criteria to modify the low frequencycoefficient in the sub-block of the original image. The experiments focus on thealgorithm robustness tests, the watermarked image were applied to noiseattack, JPEG compression attacks, filtering attacks and geometric attacks. Theexperimental results show that the robustness of the algorithm is still verystrong, and the transparency can be a very good guarantee.This paper presents a new SVD digital image watermarking algorithmbased on wavelet transform. For watermark embedding, the original image isdone twice wavelet decomposition. After that we embed watermark intoreference image by modifying the singular values of the approximationcoefficient using the singular values of the watermark. Due to the nice stabilityof the image singular values and more focused image energy after wavelettransform, the MATLAB simulation results show that the proposed scheme isable to withstand a variety of attacks and can be used for copyright protection.In addition, the experiment found that the robustness of shear and meanfiltering attack is poor, so it adds sub-blocks ideas into algorithm to solute thisproblem. This paper tried to achieve digital watermarking algorithm based oncompressed sensing. Compressed sensing theory appeared nearly ten yearstime, it has penetrated into various fields of communications and informationprocessing, such as medical image processing, remote sensing imageprocessing, and so on. With the three compressed sensing process, such asthe sparse signal process, the sparse signal observation process, and thesparse signal reconstruction process, this algorithm gradually embedwatermarking to the original image. Robustness tests show that the algorithmcan resist conventional attack, but its robustness is poor in the case ofmalicious attacks. Nevertheless, the algorithm used random Gaussian matrixin the observation process to greatly improve the security of the watermark.In the grim security situation, the joint use of vary algorithms become thetrend of development. The proposed algorithm is a non-blind watermark, thewatermark extraction process requires the participation of the original image,which has restricted the development of the algorithm, and the blind watermarkembedding and extraction is further research direction.