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Digital Image Steganography
Kolarčík, Tomáš ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
This bachelor thesis deals with digital image steganography and implements some of the available methods. This thesis describes steganography on a general level, it's history and it's current form. It also shows it's classification according to the type of carrier, the classification of the methods according to the style of hiding data and the influence of the hidden information. The primary subject of this thesis is image steganography, where facts that allow imperceptibly hide data inside image are described. A great part of this thesis is dedicated to the characteristics of the methods, which we observe and to the methods themselves. All of the methods described are implemented in a graphical and console application. The created application provides multiple image formats for hiding. In the last part, testing is performed in terms of capacity, imperceptibility and robustness.
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Digital Steganalysis
Molnár, Ondřej ; Nevoral, Jan (referee) ; Strnadel, Josef (advisor)
Steganalysis is the opposite science discipline of the steganography - which is an art of information hiding . Steganography deals with embedding of secret messages to different types of media. The most commonly used cover media in modern steganography are image files . This bachelor's thesis creates an overview of known steganograpy and steganalysis methods . It also describes practical implementation of application that is able to detect hidden information in image.
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Digital Image Steganography
Mazánek, Antonín ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
This bachelor's thesis introduces the steganography scientific discipline. It presents its ancient and relative recent history, mentions its current use and outlines the possible directions for steganography future. It introduces steganography into context of hiding information superior domain and highlights differences between other methods in this domain. It describes steganography subdivisions and closer deals with digital image steganography. It presents some known methods and types of digital image data. The thesis also contains more detailed description of image data in PNG format. It describes the implementation of LSB and PVD steganography methods with images in PNG format as cover object and evaluates their key properties, namely: imperceptibility, capacity and robustness. At the end of the thesis, the author's reflection on the results and possibilities of further modifications of the mentioned methods is given.
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Software for data hiding in image files
Morkus, Filip ; Říha, Kamil (referee) ; Burda, Karel (advisor)
In my master's thesis I start fromthedescriptionofthebasics and thebeginningsofsteganography, itsmethods and purposes. Detaileddescriptionof BMP fileswithhidden data follows. A filestructureisanalysedintothesmallestdetails to avoiddamagingfilewhilehiding. At thesametime to make profit oftheinformationincluded in a fileheader in the most effectiveway. Anotheraimwas to explain a principalofsteganographicalmethoditself, usedforhiding data into BMP file. Based on these findings, a programmeconceptwasdesigned and consequentlythatprogrammewas made. Itcarriesoutthehiding and revealing data intothe image files. Directionsfor use are made to thisprogramme and thereisalso a demo ofthefeaturesdescribingeach step. At the end ofmymaster's thesis anattentionispaid to thoseinfluencesthatcanbelimitingforthismethod. Exceeding these limitswouldlead to breakingthesteganographicalmethod, whichmeansrevealingthehidden data.
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Acceleration of Data Compression Algorithms Using GPU
Cacek, Pavel ; Drábek, Vladimír (referee) ; Šimek, Václav (advisor)
This bachelor's thesis is dealing with possibility of acceleration compression algorithm on graphical card. I have studied specifically the compression algorithm JPEG, which is used for compression image data. The text first introduced technology, which give access to us use computational power of graphics cards. The work is also focused on the theoretical description of the JPEG and subsequently is describe its implementation using OpenCL and NVIDIA CUDA. Finally, there is a comparison of performance this GPGPU technologies.
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The Role of Bmp4 and Bmp8b proteins in genesis of mouse primordial germ cells
Vegrichtová, Markéta ; Tlapáková, Tereza (advisor) ; Petelák, Aleš (referee)
Primordial germ cells are precursors of sexual breeding organisms. For induction of their formation are necessary growth factors from extraembryonic ectoderm. There are key proteins BMP4 a BMP8b among these factors. These proteins form both homodimers and heterodimers and through receptor complexes and SMAD proteins are indicating the competent cells of proximal epiblast, which give rise to the primordial germ cells and other structures of embryonic mezoderm. Although BMP4 and BMP8b proteins signal similarly, they are mutually indispensable and though for induction of primordial germ cells are both necessary. Up to now, it was proposed several models of their interaction, but not yet completely accurate.
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Digital Steganalysis
Molnár, Ondřej ; Nevoral, Jan (referee) ; Strnadel, Josef (advisor)
Steganalysis is the opposite science discipline of the steganography - which is an art of information hiding . Steganography deals with embedding of secret messages to different types of media. The most commonly used cover media in modern steganography are image files . This bachelor's thesis creates an overview of known steganograpy and steganalysis methods . It also describes practical implementation of application that is able to detect hidden information in image.
|
|
|
Digital Image Steganography
Kolarčík, Tomáš ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
This bachelor thesis deals with digital image steganography and implements some of the available methods. This thesis describes steganography on a general level, it's history and it's current form. It also shows it's classification according to the type of carrier, the classification of the methods according to the style of hiding data and the influence of the hidden information. The primary subject of this thesis is image steganography, where facts that allow imperceptibly hide data inside image are described. A great part of this thesis is dedicated to the characteristics of the methods, which we observe and to the methods themselves. All of the methods described are implemented in a graphical and console application. The created application provides multiple image formats for hiding. In the last part, testing is performed in terms of capacity, imperceptibility and robustness.
|
|
|
Digital Image Steganography
Mazánek, Antonín ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
This bachelor's thesis introduces the steganography scientific discipline. It presents its ancient and relative recent history, mentions its current use and outlines the possible directions for steganography future. It introduces steganography into context of hiding information superior domain and highlights differences between other methods in this domain. It describes steganography subdivisions and closer deals with digital image steganography. It presents some known methods and types of digital image data. The thesis also contains more detailed description of image data in PNG format. It describes the implementation of LSB and PVD steganography methods with images in PNG format as cover object and evaluates their key properties, namely: imperceptibility, capacity and robustness. At the end of the thesis, the author's reflection on the results and possibilities of further modifications of the mentioned methods is given.
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The Role of Bmp4 and Bmp8b proteins in genesis of mouse primordial germ cells
Vegrichtová, Markéta ; Tlapáková, Tereza (advisor) ; Petelák, Aleš (referee)
Primordial germ cells are precursors of sexual breeding organisms. For induction of their formation are necessary growth factors from extraembryonic ectoderm. There are key proteins BMP4 a BMP8b among these factors. These proteins form both homodimers and heterodimers and through receptor complexes and SMAD proteins are indicating the competent cells of proximal epiblast, which give rise to the primordial germ cells and other structures of embryonic mezoderm. Although BMP4 and BMP8b proteins signal similarly, they are mutually indispensable and though for induction of primordial germ cells are both necessary. Up to now, it was proposed several models of their interaction, but not yet completely accurate.
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