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Digital Image Watermarking
Šujan, Miroslav ; Říha, Kamil (referee) ; Číka, Petr (advisor)
The bachelor´s thesis deals with the problem of static digital watermarking in frequency domain. It is a process of adding secret information to the original data without any negative influence to them, while in the same time making sure that the identification and hidden watermark cannot be removed easily. The main aim of this thesis is to sum up the current techniques of watermarking, to carry out of two watermarking techniques and a test of resistance to attacks against them.
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Advanced Methods to Multimedia Data Protection
Mikulčík, Ondřej ; Zukal, Martin (referee) ; Číka, Petr (advisor)
To protect the the copyright of multimedia works have been developed watermarking techniques, that insert an invisible watermark to the original data. The aim of this thesis was to explore modern watermarking techniques, choose three of them and realize them. Also test them, evaluate their properties and possibly improve them. All methods insert a watermark into luminance component of the original image, and work with binary or black and white watermark. All techniques work in the frequency domain using discrete wavelet transform. For the implementation of methods, have been developed software named "Watermarking" that has been programmed in JAVA Version 7. The first chapter describes the types of watermarks, the general process of insertion and extraction, watermarking systems and important feature requests of embedded water- marks. In addition, qualitative methods are mentioned for their comparisons and testing. The chapter also contains a theoretical description of the used transformations and functions. In the second chapter is described the user interface of the software "Water- marking". Chapters three and four contain a theoretical description of the implemented methods and description of implementation of insertion and extraction processes of the watermark. Also there are discussed the exact procedures for testing, the sample data, and the results which are clearly displayed in the tables. The fifth chapter discusses in detail the results obtained in testing the robustness of the watermark, using the software StirMark. In the conclusion are evaluated the advantages and disadvantages of methods and quality parameters.
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Protecting of image data
Nováček, Aleš ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
Bachelor´s thesis is about protection of digital images, especially about modern watermarking techniques. It consists of three main parts. The first one is the theoretical part, that describes watermarking terminology, techniques of embeding and detection of watermark, watermarking applications and watermarking requirements such as robustness and impercebility. The second and third part compares two methods of watermarking. Both methods are based on the transformation of image to the frequency domain. The first method uses discrete cosine transformation and the second one discrete wavelet transformation. Method using DCT embeds watermark by swaping DCT coefficients. The second method embeds watermark by modifying some coefficients of DWT decomposition according to the equation vi´= vi (1+sxi ), where vi´ is a coefficient of watermarked image, vi is a coefficient of original image, xi is pixel of watermark and s is scale factor, constant, that affects robustness of watermark.
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Neural networks in audio signal watermarking algorithms
Kaňa, Ondřej ; Smékal, Zdeněk (referee) ; Zezula, Radek (advisor)
Digital watermarking is a technique for digital multimedia copyright protection. The robustness and the imperceptibility are the main requirements of the watermark. This thesis deals with watermarking audio signals using artificial neural networks. There is described audio watermarking method in the DCT domain. Method is based on human psychoacoustic model and the techniques of neural networks.
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Watermarking of static images
Bambuch, Petr ; Burda, Karel (referee) ; Číka, Petr (advisor)
The thesis deals with the security of static images. The main aim is to embed the watermark into the original data so effectively, to avoid removal of the watermark with the use of simple and fast attacks methods. With developing of the watermarking techniques the technique of attacks are improved and developed also. The main aim of the attacks is to remove and devalue the hidden watermark in the image. The goal of the thesis is to check current techniques of static image watermarking and implement two methods of watermarking, which are to be tested for robustness against attacks.
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Digital Image Watermarking
Šujan, Miroslav ; Říha, Kamil (referee) ; Číka, Petr (advisor)
The bachelor´s thesis deals with the problem of static digital watermarking in frequency domain. It is a process of adding secret information to the original data without any negative influence to them, while in the same time making sure that the identification and hidden watermark cannot be removed easily. The main aim of this thesis is to sum up the current techniques of watermarking, to carry out of two watermarking techniques and a test of resistance to attacks against them.
|
|
|
Protecting of image data
Nováček, Aleš ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
Bachelor´s thesis is about protection of digital images, especially about modern watermarking techniques. It consists of three main parts. The first one is the theoretical part, that describes watermarking terminology, techniques of embeding and detection of watermark, watermarking applications and watermarking requirements such as robustness and impercebility. The second and third part compares two methods of watermarking. Both methods are based on the transformation of image to the frequency domain. The first method uses discrete cosine transformation and the second one discrete wavelet transformation. Method using DCT embeds watermark by swaping DCT coefficients. The second method embeds watermark by modifying some coefficients of DWT decomposition according to the equation vi´= vi (1+sxi ), where vi´ is a coefficient of watermarked image, vi is a coefficient of original image, xi is pixel of watermark and s is scale factor, constant, that affects robustness of watermark.
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Advanced Methods to Multimedia Data Protection
Mikulčík, Ondřej ; Zukal, Martin (referee) ; Číka, Petr (advisor)
To protect the the copyright of multimedia works have been developed watermarking techniques, that insert an invisible watermark to the original data. The aim of this thesis was to explore modern watermarking techniques, choose three of them and realize them. Also test them, evaluate their properties and possibly improve them. All methods insert a watermark into luminance component of the original image, and work with binary or black and white watermark. All techniques work in the frequency domain using discrete wavelet transform. For the implementation of methods, have been developed software named "Watermarking" that has been programmed in JAVA Version 7. The first chapter describes the types of watermarks, the general process of insertion and extraction, watermarking systems and important feature requests of embedded water- marks. In addition, qualitative methods are mentioned for their comparisons and testing. The chapter also contains a theoretical description of the used transformations and functions. In the second chapter is described the user interface of the software "Water- marking". Chapters three and four contain a theoretical description of the implemented methods and description of implementation of insertion and extraction processes of the watermark. Also there are discussed the exact procedures for testing, the sample data, and the results which are clearly displayed in the tables. The fifth chapter discusses in detail the results obtained in testing the robustness of the watermark, using the software StirMark. In the conclusion are evaluated the advantages and disadvantages of methods and quality parameters.
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Neural networks in audio signal watermarking algorithms
Kaňa, Ondřej ; Smékal, Zdeněk (referee) ; Zezula, Radek (advisor)
Digital watermarking is a technique for digital multimedia copyright protection. The robustness and the imperceptibility are the main requirements of the watermark. This thesis deals with watermarking audio signals using artificial neural networks. There is described audio watermarking method in the DCT domain. Method is based on human psychoacoustic model and the techniques of neural networks.
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Neural networks in audio signal watermarking algorithms
Kaňa, Ondřej ; Smékal, Zdeněk (referee) ; Zezula, Radek (advisor)
Digital watermarking is a technique for digital multimedia copyright protection. The robustness and the imperceptibility are the main requirements of the watermark. This thesis deals with watermarking audio signals using artificial neural networks. There is described audio watermarking method in the DCT domain. Method is based on human psychoacoustic model and the techniques of neural networks.
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