Robust Watermarking Techniques Based On Image Feature

With the development of the information technology, copyright protection of digitalproducts becomes a more and more serious issue. Robust digital watermarking, which isconsidered as a brand-new information security technology, has been regarded as a promisingway to protect the copyright. Because of the universality and significance existing in digitalimage, this dissertation mainly do reseaches on robust image watermarking techniques. Themain research work and contributions are as follows:1On the basis of the descriptions about watermarking concepts, we analyse the existingwatermarking attack technologies closely related to robust watermarking, and discuss therobust watermarking technology against geometric attacks, the research emphasis and difficulty,through classification comparison. At last, we make a summary and conclusion about majorproblems that robust watermarking faces.2A watermarking algorithm based on the local feature is proposed to improve the holisticrobustness.The algorithm chooses suitable operateors to extract steady features.By designingpartition means of the local feature regions (LFR), we construct LFR which is robust usingsteady features.Then we combine the normalization with the selection scheme of embeddingregions based on the DWT transformation to realize the embedding and extraction ofwatermark. Experimental results show that the proposed scheme is not only robust againstcommon signals processing, but also robust against the geometric attacks.3. Aiming at the issue that some application situation of copyright protect requires biggishwatermark embedding capacity, we propose a robust watermark algorithm based on featuretemplate. The algorithm combines the template matching strategy with the feature extractingtechnology. First, we complete the embedding of watermark based on DWT transformationand SVD technology, to ensure the watermark capacity and rubustness to the common signalsprocessing. Then, we rectify the geometric distortion by using of the feature template which isconstructed by feature information, thus makes the algorithm is robust against geometricattacks. Experimental results show that the proposed scheme not only is robust against bothcommon signals processing and geometric attacks, but also can meet requirement ofembedding capacity.4We apply robust digital watermarking technology to digital image copyright protectingsystem based on the analysis and reseach of copyright management technology, and design andactualize the system.Finally, the paper gives a positive outlook for the development prospect and research direction of watermark technology.