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Image Transformations
Novák, Radim ; Juránek, Roman (referee) ; Venera, Jiří (advisor)
The main goal of this thesis is to introduce two fundamental geometric transformations in 2D space - by changing the resolution together with related image resampling and image rotation. Also brightness interpolation, technique of mapping and other problems related to the topic are explained there, i.e. Fourier transformations, problem with aliasing and technique of aliasing suppression.
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Implementation of Waveshaper Audio Effect
Leitgeb, David ; Miklánek, Štěpán (referee) ; Schimmel, Jiří (advisor)
The aim of this thesis is the implementation of a non-linear audio effect called waveshaper. This type of distortion effect contains the following building blocks: user defined transfer function, several types of filters and an oversampling processor with multiple stages of oversampling. The first prototype of this audio effect was implemented using Matlab and its Audio Toolbox extension. Due to certain limitations of this prototype, the whole audio effect was later completely rewritten in C++. This new implementation uses the JUCE framework which is mainly used for audio application development. The transition to this framework allowed real time editing of the transfer function and a VST3 build of the effect. In addition to a brief introduction of the used system types, motivation for oversampling and the description of the implementation for both prototypes, this thesis also includes graphical examples demonstrating their correct functionality. Audio files related to these examples are included in the electronic attachment.
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Evaluation of influence of interpolation methods on coregistration of radar images
Slačíková, Jana ; Potůčková, Markéta (advisor) ; Hlaváčová, Ivana (referee)
Evaluation of influence of interpolation methods on coregistration of radar images Abstract SAR interferogram processing requires subpixel coregistration of SAR image pair for accurate phase differencing. Errors in alignment introduce phase noise in SAR interferogram. Last step in coregistration is resampling one of SAR images. Also this step introduces errors in SAR interferogram. The resampling algorithms Nearest Neighbor, Bilinear interpolation, Cubic Convolution and advanced methods such as Raised Cosine kernel, Knab interpolation kernel and Truncated Sinc were tested on ERS tandem data and compared. The results were compared with the theory and simulations of earlier investigations (Hanssen, Bamler, 1999), (Migliaccio, Bruno, 2003) and (Cho ... [et al.], 2005). The main experiment in this work was to examine and compare resampling methods on real data to evaluate their effect on the interferometric phase quality and DEM generation. The coregistration performance was evaluated by the coherence (Touzi ... [et al.], 1999) and the sum of phase differences (Li ... [et al.], 2004). No evidence showed that computationally intensive algorithms produced better quality of interferogram than Cubic Convolution. The possibilities of evaluating by means of the accuracy of the final InSAR DEM (Li, Bethel, 2008) were...
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Interactive web applications for teaching purposes in the field of signal processing
Kuba, Michael ; Rajmic, Pavel (referee) ; Záviška, Pavel (advisor)
This thesis deals with selected topics of signal processing. The aim of the project is the implementation of four interactive web applications in JavaScript, intended for teaching purposes. These applications deal with following topics: rational number resampling of the discrete signal, mean and root mean square signal values, discrete linear and circular convolution in 1D, and discrete cross-correlation. The thesis is divided into the theoretical and the practical part. There is a theroretical foreword of topics the applications deal with, including an introduction to signals followed by a description of functionality and the user interface of created applications.
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Design of low order high OSR discrete time delta-sigma modulator for audio applications
Dohnal, Jaroslav ; Kledrowetz, Vilém (referee) ; Háze, Jiří (advisor)
Tato diplomová práce si klade za cíl seznámit čtenáře se základním konceptem a principy jednosmyčkových modulátorů . Diplomová práce ozřejmuje čtenáři problematiku delta-sigma () modulátorů s jednou zpětnovazební smyčkou. Zabývá se základními principy převzorkování u číslicově-analogových převodníků a rozšiřuje je o teorii tvarování spektra šumu. Vycházeje z této teorie jsou navrženy tři jednosmyčkové modulátory, které běží na 1024 OSR jako alternativa k běžně používáným modulátorům vysokých řádů. Modulátory jsou implementovány do FPGA společně s rekonstrukčním filtrem a podpůrnými bloky. Nakonec byl zkonstruován hardwarový prototyp pro vyhodnocení implementace navrženého DAC.
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Interactive web applications for support of teaching signal processing
Mašek, Petr ; Rajmic, Pavel (referee) ; Záviška, Pavel (advisor)
The bachelor thesis deals with the topic of processing one-dimensional signals. Five interactive web applications have been created in JavaScript to support teaching. These are applets that relate to the following topics: rational number resampling of the discrete signal, mean and root mean square signal values, discrete linear and circular convolution in 1D, and discrete cross correlation. The thesis introduces each topic by a theoretical foreword, followed by description of implementation and user interface of the created applications and further there is a commentary on the development and testing of applets.
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Verification of the Vdip method on the physical model of the MV network
Krčál, Vít ; Drápela, Jiří (referee) ; Topolánek, David (advisor)
This Master's thesis is focused on creating of an algorithm which calculates changes of negative-sequence voltages and currents from their instantaneous values. That allows to conduct localization of asymmetrical faults in MV network in line with the Vdip method, which is based on monitoring the changes of negative-sequence components at distribution substations and at a sub-transmission station. The algorithm is being developed in Matlab environment with continuous implementation of partial procedures which are being assessed and compared with each other. A study of phasor estimating methods is carried out with pointing out related problems which are mainly caused by Ripple control and deviation of system frequency from its nominal value. Optimization precautions are designed to mitigate these problems. For elimination of the Ripple control effects a method based on averaging is presented. The deviation of system frequency is dealt with by resampling the original data recordings. The analysis processes are tested by both simulation signals and real measured data. The optimized algorithm enables precise calculation of negative-sequence components changes which is the main contribution of this thesis. The constructed algorithm is used in verification of the Vdip method on physical model of MV network. For these purposes a simple distribution network is created within which ground faults on different places and with different resistances are realised. The results of localization are not convincing which is mainly caused by specific features of laboratory power line models which are constructed with heterogenous parameters.
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Implemetation of signal processing problems for teaching purposes
Ševčík, Zdeněk ; Rajmic, Pavel (referee) ; Mangová, Marie (advisor)
This thesis is focused on Fourier series, phasor diagram, signal resampling and amplitude modulation. All of there problems are analyzed in theoretical part of thesis. Here are derived all three form of Fourier series, described signal sampling, decimation and interpolation. Next thesis is focused on signal modulation and closer deal with amplitude modulation of harmonic and inharmonic signal. In practical part is example of calculation of Fourier siries for a specific signal, example of signal resampling and example of amplitude modulation for harmonic and inharmonic signal. Objective of practical part is creates programs focused on these problems. Programs should be interactive and their purpose is demonstrate the problem to students.
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Evaluation of Methods of Stereo Image Processing
Juráček, Ivo ; Španěl, Michal (referee) ; Zemčík, Pavel (advisor)
This thesis addresses the correlation between two pictures and its application to a real example using a camera which is a part of a stereo camera. It suggests how to use correlation to find specific patterns in pictures whereas it is possible to calculate the movement between two scaled pictures which is done by resampling. The accuracy of correlation is then shown when pictures are compensated using affine transformation in order to verify the accuracy of correlation. To further increase the correlation accuracy, it is possible to use a corner detector, it finds main points in a shot and then it searches for a match in another shot using correlation. Final results using this method are also mentioned in this thesis.
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