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Image Compression Using the Wavelet Transform
Urbánek, Pavel ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This thesis is focused on subject of image compression using wavelet transform. The first part of this document provides reader with information about image compression, presents well known contemporary algorithms and looks into details of wavelet compression and following encoding schemes. Both JPEG and JPEG 2000 standards are introduced. Second part of this document analyzes and describes implementation of image compression tool including inovations and optimalizations. The third part is dedicated to comparison and evaluation of achievements.
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Wavelet-type compression of images using distributed computing in Matlab
Seifert, David ; Smékal, Zdeněk (referee) ; Rajmic, Pavel (advisor)
The thesis deals with the possibility of wavelet compression in Matlab. In the beginning it only made me review the history of Wavelet analysis and its possibilities. Then followed a general kampitola wavelet transform, basic knowledge about it. It also identified Mallátův pyramidal algorithm. The following chapter on the DWT and its use for processing the image compression. Chapter One consists of the implementation of compression in Matlab. Here is the reason for dividing the image into blocks. There is also mention 2 basic methods of processing using Matlab, and parallel and distributed. In another part of the chapter followed by a description of the program itself. In the last part of the chapter is set to use this program with different parameters of the elective program.
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Image Compression Using Wavelets
Mokrejš, Jiří ; Kyselý, František (referee) ; Říha, Kamil (advisor)
This bachelor´s thesis describes issues of wavelet compression, which is today already in common use mainly at work with digital photographs or other pictures. Saving of space regarding sizes of files is the main reason of that. There are main image formats and types of compression suitable for editing pictures desribed in this thesis. In case of lossy image compression, distortion occurs and blocking artefacts can be created. It is unwanted effect that´s why it is neccesary to use suitable data stream, compression´s rate or coding type. So the focus is on discrete wavelet transform, which uses so-called wavelets and the Haar´s wavelet is the best known of all. Next chapter of this work explores colour spaces, in which can be a picture displayed. In case of coding and encoding it is model RGB and YCbCr. Not least there is mentioned term of picture decomposition. It is possible to demonstrate mentioned functions on created java aplication, which is part of this bachelor´s thesis.
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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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Applications of wavelet transform in Mathematica and Sage
Novotný, Radek ; Trzos, Michal (referee) ; Rajmic, Pavel (advisor)
This thesis focuses on image processing using wavelet transform. The usage of wavelet transform is analysed especially for image compression and image noise reduction purposes. The analysis describes in detail aspects and application of the following wavelet transform methods: CWT, DWT, DTWT, 2D DWT. The thesis further explains the meaning of the mother wavelet and studies certain specific kinds of wavelets, kinds of thresholding and its purposes and also touches on the JPEG2000 standard. Mathematica and Sage software packages were used to design algorithms for image compression and image noise reduction, utilising relevant wavelet transform findings. The concluding part of the thesis compares the two software packages and results obtained using different algorithms.
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Applications of wavelet transform in Mathematica and Sage
Novotný, Radek ; Trzos, Michal (referee) ; Rajmic, Pavel (advisor)
This thesis focuses on image processing using wavelet transform. The usage of wavelet transform is analysed especially for image compression and image noise reduction purposes. The analysis describes in detail aspects and application of the following wavelet transform methods: CWT, DWT, DTWT, 2D DWT. The thesis further explains the meaning of the mother wavelet and studies certain specific kinds of wavelets, kinds of thresholding and its purposes and also touches on the JPEG2000 standard. Mathematica and Sage software packages were used to design algorithms for image compression and image noise reduction, utilising relevant wavelet transform findings. The concluding part of the thesis compares the two software packages and results obtained using different algorithms.
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The use of genomic signal compression for classification and identification of organisms
Sedlář, Karel ; Vítek, Martin (referee) ; Škutková, Helena (advisor)
Modern classification of organisms is performed on molecular data. These methods rely on multiple alignment of sequences of characters which make them computationally demanding. Only small parts of genomes can be compared in reasonable time. In this paper, the novel algorithm based on conversion of the whole genome sequences to cumulative phase signals is presented. Dyadic wavelet transform is used for lossy compression of signals by redundant frequency bands elimination. Signal classification is then performed as a cluster analysis using Euclidian metrics where multiple alignment is replaced by dynamic time warping.
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Educational video codec
Dvořák, Martin ; Hála, Ondřej (referee) ; Slanina, Martin (advisor)
The first goal of diploma thesis is to study the basic principles of video signal compression. Introduction to techniques used to reduce irrelevancy and redundancy in the video signal. The second goal is, on the basis of information about compression tools, implement the individual compression tools in the programming environment of Matlab and assemble simple model of the video codec. Diploma thesis contains a description of the three basic blocks, namely - interframe coding, intraframe coding and coding with variable length word - according the standard MPEG-2.
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Watermarking of digital data
Kupka, Jan ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
The main aim of this project is to implement two different types of the watermarking algorithm in frequency (transforamtion) domain. Because of the huge amount of the watermarking algorithms is this thesis dedicated to the watermarking methods in the frequency domain. These methods use kind of transformation implemented on the original data, the second step is modification of transformation coeficients. This project is dedicated to the methods which use discrete wavelet transformation. Nowdays the most popular transformation, which meets the best efforts. The aim of every method is to embeed the watermark into the original data so precisly, that none observer can recognize any change between the original and watermarked data. On the contrary, watermarked picture should be as resistant to the attacks as possible. By the term of attack, we understand all the ways, that disable watermark extraction. The watermark method robustness will be tested with the use of Checkmark program.
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