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Parallel signal processing with help of GPU
Václavík, Jiří ; Frýza, Tomáš (referee) ; Mego, Roman (advisor)
In the introduction, the bachelor thesis outlines the origins of modern graphic processors. The theoretical part of the text describes the minimum of required information from parallel programming model essential to program simple DSP algorithms. The next part elaborate on three common DSP algorithms, finite impulse response filter, naive implementation of discrete cosine transform type II, and fast Fourier transform. To demonstrate parallel capability of GPU, algorithm for JPEG compression was chosen as JPEG compression is favorable because it illustrates both advantages and disadvantages of parallel data processing on GPU, and compromises needed to be considered.
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Hierarchical Coding of Moving Pictures
Špaček, Milan ; Rášo, Ondřej (referee) ; Schimmel, Jiří (advisor)
Bachelor‘s thesis deals with hierarchical coding – scaling – of moving pictures in currently widely used compression algorithms MPEG-2 and MPEG-4. Scaling is the process whereby the encoded data stream is divided into graduated layers, adapted especially to the possibilities of transmission media and capabilities of terminal devices. The content of the base layer is a signal with reduced quality. The content of one or more extension layers is a supplementary picture information, completing the signal to a full quality form. The decoder, depending on its abilities and external circumstances, can decode only the relevant layers from the received bitstream. The thesis focuses in the theoretical part on the detailed description of encoding and decoding video signal according to MPEG standards using three types of scalability. In the concrete, the spatial, qualitative SNR and Fine granular scalability are mentioned. In the practical part of thesis was created an educational application in Matlab environment with its own graphical user interface, which implements the functions performing spatial, qualitative SNR and Fine granular scalability. Based on the user-specified input parameters, it performs scaling the image and then displays the outputs of individual layers after scaling and after the image reconstruction. The input of the programme, in which a hierarchical coding is done, is the image in bitmap format with any size in RGB format.
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Texture Synthesis
Havelka, Robert ; Štancl, Vít (referee) ; Švub, Miroslav (advisor)
This thesis deals with texturing, its importance and basic list of the processes during texture synthetising is included. Texture generating is mainly described from the procedural generator point of view. There is also explained the sense of using Fourier's transformation and its simplified version, the discreet cosine transformation. For texture modiffication, Gaussian noise and gaussian filter is used. The convolution theorem is applied for the texture mixing. Within the scope of this thesis, there is also described the application implementation, which enables experimenting with texture creating.
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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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Comparison of compression algorithms for high definition video
Dvořák, Martin ; Polák, Ladislav (referee) ; Slanina, Martin (advisor)
Bachelor's thesis deals with comparison and analysis of various instruments of the present-day compression algorithms used to compress high-definition video. Video sequences require a large amount of memory for their storage and take up bandwidth for their transmission, so it is necessary to compress video signals with regard to the quality of video after decompressing. The work focuses mainly on the differences between the algorithms and overall performance. Part of this work is a compressed video database, comparing the performance of different algorithms and the subjective quality of compressed video.
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Comparison of Video Codecs
Urbánek, Pavel ; Svoboda, Pavel (referee) ; Bařina, David (advisor)
This thesis is aimed at analysis of video codecs and their comparison. First part of this document provides reader with the basic information on encoding and decoding process including high level description of often used algorithms. It describes codecs and the process of standardization. Second part is focused on test specifications and codecs comparsion itself including conclusion. PSNR, SSim and BD-PSNR are key methods used for comparing codecs.
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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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Video stream objective quality evaluation in MATLAB
Noghe, Petr ; Slanina, Martin (referee) ; Polák, Ladislav (advisor)
This work deals with the picture and video objective quality evaluation in MATLAB. The first part of this work describes the methods of the assessment of picture and video quality. The second part focused on the introduction of the source image coding. For the objective image and video quality evaluation an appropriate application in MATLAB was created. For the testing of the created application a several pictures and videos with different properties were used. Finally, obtained results are evaluated and discussed.
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Picture Quality Analysis in Digital Television Systems
Bednarz, Robin ; Slanina, Martin (referee) ; Kratochvíl, Tomáš (advisor)
Diploma thesis deals with the analysis of quality in digital television systems and contains theoretical description of subjective and objective assessment of quality picture methods. The thesis contains short-term and long-term analysis of quality picture of terrestrial television DVB-T. Measurements and experimentations were carried out with the help of Rohde&Schwarz DVQ analyzer of picture quality and software MPEG-2 Quality Monitor and MPEG-2 Elementary stream analyzer.
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Keyword Spotting Implementation to Mobil Phone (Symbian 60)
Cipr, Tomáš ; Schwarz, Petr (referee) ; Szőke, Igor (advisor)
Keyword spotting is one of the many applications of automatic speech recognition. Its purpose is determining spots in given utterance in which some of the specified words were spoken. Keyword spotting has a great potential to enhance performance of new applications as well as the existing ones. An example could be a mobile phone voice control. Due to OS Symbian's coming to the market it is even possible for end user to implement a keyword spotting for a mobile phone on his or her own. The thesis describes theoretical prerequisites for keyword spotting and its implementation. Firstly the OS Symbian is presented with respect to the given task. Secondly each step of keyword spotting process is described. Finally the object design of keyword spotter is presented followed by implementation description. The thesis concludes with results review and notes on possible improvements.
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