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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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Steganography
Podhorský, Jiří ; Kubíček, Radek (referee) ; Zemčík, Pavel (advisor)
This bachelor project focuses on steganography and presents new modifications of known metods steganography and their implementation. It also presents implementation of adaptive metod Neighbours, for comparison. Both of the metods are based on the "Least Significant Bit" exploitation. It is also demonstrated that newly proposed modification can be used in other metods of steganography. The purpose of proposed method is to encode a secret information into the digital image so that the information is not easily detectable.
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Watermarking as Document Protection
Segedy, Patrik ; Kočí, Radek (referee) ; Hanáček, Petr (advisor)
This thesis is dealing with document protection using a digital watermarking. First, a watermark characteristics are presented. Then, different usages of the watermarking are discussed. Next part of the thesis is dedicated to current development in watermarking field. It is aimed at various principles of watermark embedding into different multimedia types. Subsequently, a watermarking scheme for still images is proposed and implemented. Finally, the watermarking scheme undergoes attacks, which should damage embedded watermark. Attacked watermark is then extracted and compared to the embedded watermark.
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Invisible watermarking method for images
Trbušek, Pavel ; Říha, Kamil (referee) ; Malý, Jan (advisor)
Bachelor´s thesis deals with embedding of invisible watermark into image. The methods used for reach the main objective of this thesis are given in the first part. I mention three methods: Discrete Cosine Transform method, Discrete Wavelet Transform method and Set Partitioning in Hierarchical Trees method. In the second part I describe implementation of Discrete Wavelet Transform method and Set Partitioning in Hierarchical Trees method in MATLAB setting. The last part deals with the test of the watermark endurance to geometrical attacks. I summarize the results of the watermark endurance test are very satisfactory even by the disruption of the image quality.
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Image watermarking in frequency domain
Štrbíková, Tatiana ; Rajmic, Pavel (referee) ; Číka, Petr (advisor)
This thesis analyze digital watermarking. At first we can read about watermarking in generally. Secondarily, it considers about possibilities of watermarking, therefore about different ways of watermarking. Methods of digital watermarking we can divide into three main categories: spatial domain watermarking, frequency domain watermarking and spread spectrum watermarking. In detail there is described frequency domain watermarking. Two methods are compared. First method, which use DCT (Discrete cosine transformation) and second metohd, which use DWT (Discrete wavelet transformation). Finally we can found out, which method seems to be better.
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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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Image watermarking
Štágl, Luboš ; Zezula, Radek (referee) ; Číka, Petr (advisor)
This diploma thesis is concerned in static pictures Security problems. That means, additional informations (watermark) are embedded to the original picture in a specific way. This complex picture structure (watermark) should be unremoval by different attacks runing processes. The main goal of this diploma thesis is realize two separated methods digital data watermarking in MATLAB program. For reason of a quite large scale of different watermarking methods are chosen at this time only two of take were choosen. First of the methods is Watermark injection in the spatial domain and the second in the freuquency domain. Both methods are set up in a special way and finish goals of the process. Expected result are, that digital picture user doesn't know about the watermarking technique was aplied on this picture and the watermarking data are the most resistant as possible as can be. These attacks were simulated in Checkmark program.
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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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VST Plug-IN for audio signal watermarking
Henzl, David ; Schimmel, Jiří (referee) ; Zezula, Radek (advisor)
This thesis deal with digital signal proccessing methods, possibilities their processing and especially audio signal watermarking like possibility safeguard author's rights of audio content. In this thesis are foreshadoweds basic audio watermarking methods and possibilities of watermark detection. To idea generation about watermarking there is described audio watermarking method known as Echo Hiding. This method embed watermarks to audio content in time-domain while watermark detection is made in kepstral-domain by using Fast Fourier Transform and correlation function. Method is implemented like VST plug - in and along with ASIO drivers that minimize signal latency provides audio signal watermarking in real - time. Aim of the first volume of this thesis is introduction of VST technology, ASIO driver and creating VST plug – in‘s. Alternative volume of thesis deal with implementation watermarking methods in conjunction with VST technology.
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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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