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The Syudy On Alogrithms Of Robust Image Watermarking Based On Transform Domain

Posted on:2012-06-29Degree:MasterType:Thesis
Country:ChinaCandidate:Y X WangFull Text:PDF
GTID:2178330338491194Subject:Communication and Information System
Abstract/Summary:PDF Full Text Request
With the rapidly development of technologies of computer, internet and communication, information security and copyright protection become an important problem needing solved urgently. Digital watermarking technology is a new and effective way to protect digital products. Therefore, the study of digital watermarking technology becomes a focus in the filed of imformation security and holds wide application prospect in several domains. According to the rationale of the digital watermarking technology, the dissertation proposes three robust watermarking algorithms based on transform domain. The main contents include three parts as shown:Firstly, a grey level image watermarking algorithm based on distributed multiresolution discrete cosine transform is proposed. The algorithm utilizes gray level image as watermark. The distributed multiresolution discrete cosine transform and singular value decomposition are used in the embedding and extraction of the watermark. The results of computer simulation show that the the proposed watermarking methods satisfy the requirements of robustness and transparency.Secondly, a blind watermarking algorithm based on discrete wavelet transform is proposed. The watermark is encrypted through Arnold transform and logistic sequence. The watermark is embedded into the abundant texture region of wavelet approximation subimage, the best abundant texture information are selected adaptively. Because of quantization embedding strategies, no original image is needed in watermarking extraction. The algorithm improves the security and robustness of the watermark.Finally, a blind watermarking algorithm in contourlet domain is proposed. The watermark is preprocessed by double encryption.The original image is decomposed by using contourlet, the low-pass subband and band-pass subband are required, then the relations of contourlet coefficients is created. According to the relations, the watermark is embedded on the contourlet low frequency coefficients. In addition, no host image is needed in watermark extraction, which is a blind watermarking algorithm. The results of computer simulation show that the the proposed watermarking methods satisfy the requirements of robustness and transparency.
Keywords/Search Tags:image processing, digital watermarking, distributed multiresolution discrete cosine transform, discrete wavelet transform, contourlet transform, robustness
PDF Full Text Request
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