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Dynamic multiple watermarking algorithm based on zero- watermark

Author: QiWenTong
Tutor: ShaoLi
School: Capital University of Economics
Course: Industrial Economics
Keywords: Digital Watermarking DCT transform DWT transform Adaptive Chaotic system Spread Spectrum Zero watermark Multiple watermarking Fragile watermark
CLC: TP309.7
Type: Master's thesis
Year: 2008
Downloads: 111
Quote: 1
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Abstract


The digitization of multimedia digital multimedia information access provides a great convenience, but also greatly improve the efficiency and accuracy of the information expressed. With the increasing popularity of multimedia digital is becoming an important source for people to obtain information, and became an important part of people's lives. At the same time, digital multimedia information copyright, confidentiality and other related issues become increasingly prominent up. Therefore, the multimedia information security has become a hot research topic. People often think that the realization of the Communications Security Encryption (Cryptography). Released after the first multimedia data files are encrypted into ciphertext, network transfer process, unlawful attacks on confidential information can not be obtained from the ciphertext, so as to achieve the purpose of copyright protection and information security, but this does not solve the problem entirely. On the one hand the encrypted file its incomprehensibility impede the dissemination of multimedia information; easily lead to the attacker's curiosity and attention the other hand multimedia information is encrypted, and cracked the possibility, and once the encrypted files after crack completely transparent. Cryptography has been considered the main means of information security, and are subject to a great deal of attention in the field of communication research applications, until recent years, only a change in this situation. People try to hide the secret information dissipated in ordinary file to track violations and provides legal protection of evidence, which is called information hiding (Information Hiding) or more strictly called steganography (Steganography). The word Steganography comes from the ancient Greek meaning is hidden inside other information will be useful or important information to conceal its existence. And encryption, the encryption system to protect the content of the information, but information camouflage to conceal their presence. Digital watermark (digital watermarking) as a new means of effective digital products copyright protection technology, international information an important branch of the hidden field. By embedding secret information - watermark (watermark) in the original data to prove ownership of the data, and thus play the role of the protection of digital copyright or completeness, and resisted the piracy of digital works or tampered. The watermark can be embedded is a paragraph of text, identification, ID, sequence number, etc.. Watermark is usually visual or hearing is not perception, with the original carrier works (such as images, audio, video, data, etc.) closely integrated and hidden which has become an inseparable part of the source data, and can be experienced without destroying the the source data or the operation of the commercial value and still exists. The paper mainly carried out in-depth research on digital image watermark technology. I read a lot of digital watermarking technology, literature and information, multimedia digital watermarking technology comes down from the status quo, and the theoretical model, the basic characteristics of digital watermarking classification. Understanding of the system based on digital watermarking technology, analysis, and summed up a lot of digital watermarking algorithms and ideas, and pointed out the advantages and disadvantages of various commonly used algorithms. For the field of digital watermarking research has focused on two aspects of the spatial domain and transform domain, respectively, by changing some pixels in the spatial domain or transform domain coefficients to embed watermark. Airspace digital watermark is directly superimposed on the signal space watermark information, thereby changing the value of the pixel of the image, usually in the watermark signal is added to the modulation of the brightness of the picture elements or ribbon. In general, the small amount of airspace arithmetic operations, the amount of information embedded concealment. However, due to some reason, the data on the image pixel is most likely to be lost in some common signal processing, so the airspace of robustness is poor. Chapter airspace watermarking algorithm do in-depth research. Transform domain the common digital watermarking algorithm commonly used transformation technology, in order to achieve the watermark signal in the frequency domain superimposed, and learn from the spread-spectrum communication technology effective encoding watermark signal, thereby enhancing the imperceptibility and robustness. Chapter embedding operator based adaptive DCT domain. Most watermarking algorithm using a pseudo-random sequence watermark, which can only answer \In some application environments, the need to embed meaningful binary image watermark. Therefore, the algorithm selects a chaotic sequence of meaningful images spread spectrum watermark information. Our proposed algorithm is carried out in the DCT domain of the upper and selects the relative importance of the frequency coefficients in the frequency domain as the location of the watermark signal is embedded. Embedded in the determination of the position of strength with embedded determined by adaptive embedding operator. Finally, the algorithm to be implemented and carried out a large number of robustness testing laboratories, experiments show that the algorithm is robust. Based on in-depth understanding of the wavelet transform, robust watermarking, zero watermark, fragile watermark, proposed a multi-watermarking algorithm in Chapter. Achieve robust watermark and fragile watermark embedding algorithm, the algorithm both copyright protection and tamper-resistant; take advantage of the characteristics of a strong zero-watermark robustness, zero-watermarking algorithm to improve the robustness of the algorithm . Then the algorithm to be implemented and carried out a large number of robustness testing laboratories, experiments show that the algorithm has a good robustness. Finally, for the weakness in the algorithm proposed the corresponding theoretical solution; proposed algorithm based zero-watermark of anti-geometric attacks and a solution to zero-watermark is meaningless watermark shortcomings of the program. Finally, this paper summarizes the proposed inadequacies in the same time, the digital watermark prospect of possible future research directions.

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CLC: > Industrial Technology > Automation technology,computer technology > Computing technology,computer technology > General issues > Security and confidentiality > Encryption and decryption
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