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Wiener Wavelet Filtering of ECG Signals
Sizov, Vasily ; Vítek, Martin (referee) ; Kozumplík, Jiří (advisor)
Tato práce se zabývá možností využití vlnkové transformace v aplikacích, které se zabývají potlačením šumu. Především se jedná o oblast filtrace signálu EKG. Úkolem je zhodnotit vliv různých parametrů nastavení samotné filtrace a zjistit jaký vliv má různé nastavení prahování wavelet koeficientů. Výsledkem práce je také stanovení hodnot prahů, stanovení nejlepšího způsobu rozkladu signálu a volba rekonstrukčních bank filtrů. Text obsahuje výsledky Wienerovy filtrace, při které byly testovány různé banky rozkladových a rekonstrukčních filtrů.Všechny popsané filtrační metody byly testovány na reálných záznamech EKG s aditivním myopotenciálním šumem. Algoritmy byly realizovány v prostředí MATLAB.
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Methods of noise suppression for speech recognition systems
Moldříková, Zuzana ; Smital, Lukáš (referee) ; Odstrčilík, Jan (advisor)
This diploma thesis deals with methods of noise suppression for speech recognition systems. In theoretical part are discussed basic terms of this topic and also methods for noise suppression. These are spectral subtraction, Wiener filtering, RASTA, mapping of spectrogram or algorithms based on noise estimation. In second part types of noise are analyzed, there is proposal and implementation of spectral subtraction method of noise suppression for speech recognition system. Also extensive testing of spectral subtractive algorithms in comparison with Wiener filter is conducted. Assessment of this testing is done with defined metrics, successfulness of recognition, recognition system score and signal to noise ratio.
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Wavelet Filtering of ECG Signals
Handl, Marek ; Smital, Lukáš (referee) ; Kozumplík, Jiří (advisor)
The work deals with the wavelet transformation, focusing on wavelet transforms with discrete time (DTWT). The practical part is focused on the implementation of redundant packet DTWT and its use in the filtration of ECG signals. The main part of the work is to design wiener filter that uses redundant packet DTWT, designed to eliminate interference myopotentials of ECG signals. The actual solution is implemented in Matlab. Testing is performed on the library CSE using noise model myopotentials used to noising original signals. For optimum parameters designed filter is used the genetic algorithm (GA). The work is carried out comparing the proposed filter redundant packet DTWT a variant of redundant dyadic DTWT.
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Motion-Blurred Image Restoration
Rajnoch, Zdeněk ; Seeman, Michal (referee) ; Bařina, David (advisor)
Goal of this thesis is restauration of motion blurred images. Motion blurr is assumed to be only over a narrow line rotated by any angle to x axis. There are several methods which are theoretically explained and compared on synthetically blurred images in several different conditions. After that motion blurred images are restaurated with some of deconvolution methods.
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Processing of cardiac cell images
Václavek, Martin ; Čmiel, Vratislav (referee) ; Odstrčilík, Jan (advisor)
This bachelor thesis is dealing with topic of digital image processing in the field of cardiac cell imaging. The aim of this thesis is familiarization with cardiac cell imaging methods and then with methods of digital image processing for a purpose of cardiocyte contractility analysis of previously captured image sequences. Basic methods of image processing and principles, which they are based on, are described. Methods for assessing cardiocyte contractility are also described. In the following part, chosen methods are implemented in MATLAB® and applied on two image sequences of cardiac cells, which were obtained using bright field microscopy.
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Sensor Security - Verification of Image Authenticity
Juráček, Ivo ; Španěl, Michal (referee) ; Zemčík, Pavel (advisor)
Diploma thesis is about image sensor security. Goal of the thesis was study data integrity gained from the image sensors. Proposed method is about source camera identification from noise characteristics in image sensors. Research was about influence of denoising algorithms applied to digital images, which was acquired from 15 different image sensors. Finally the statistical evaluation had been done from computed results.
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Automatic Generating of Subtitles by Speech Recognizer
Csintalan, György ; Plchot, Oldřich (referee) ; Schwarz, Petr (advisor)
This bachelor thesis describes developing an application for automatic generation of subtitles for films using BSAPI (Brno Speech Application Interface). At first the reader is guided to the problematics of this task and the aim of this work is described. In the next section the speech recognition API (BSAPI) is described from a theoretical point of wiev. After this, the next section is about extracting voice channel from video. The next chapter describes the implementation of the application. Further, experiments in different situations are described and possible improvements are discussed in order to achieve better outputs, for example speech enhancement by Wiener filter. In the conclusion are discussed achieved results and experiments.
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Segmentation of ECG signals based on their quality
Zobačová, Barbora ; Maršánová, Lucie (referee) ; Vítek, Martin (advisor)
This semestral thesis deals with methods for continuous estimation of the quality of the ECG signal. The theoretical part includes the functional anatomy of the heart, the basics of electrocardiography, the types of noise that can be found in the ECG records, and a description of several methods for the continuous estimation of the ECG signal quality. Next here are some approaches to segmenting ECG signals based on their quality. The practical part deals with the implementation of two methods. The first method is the SNR estimation method based on the Wiener filter. The second method is the method of segmentation of ECG signals based on their quality. Both methods were tested on artificial and real signals.
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Wiener Wavelet Filtering of ECG Signals
Sizov, Vasily ; Vítek, Martin (referee) ; Kozumplík, Jiří (advisor)
Tato práce se zabývá možností využití vlnkové transformace v aplikacích, které se zabývají potlačením šumu. Především se jedná o oblast filtrace signálu EKG. Úkolem je zhodnotit vliv různých parametrů nastavení samotné filtrace a zjistit jaký vliv má různé nastavení prahování wavelet koeficientů. Výsledkem práce je také stanovení hodnot prahů, stanovení nejlepšího způsobu rozkladu signálu a volba rekonstrukčních bank filtrů. Text obsahuje výsledky Wienerovy filtrace, při které byly testovány různé banky rozkladových a rekonstrukčních filtrů.Všechny popsané filtrační metody byly testovány na reálných záznamech EKG s aditivním myopotenciálním šumem. Algoritmy byly realizovány v prostředí MATLAB.
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Processing of cardiac cell images
Václavek, Martin ; Čmiel, Vratislav (referee) ; Odstrčilík, Jan (advisor)
This bachelor thesis is dealing with topic of digital image processing in the field of cardiac cell imaging. The aim of this thesis is familiarization with cardiac cell imaging methods and then with methods of digital image processing for a purpose of cardiocyte contractility analysis of previously captured image sequences. Basic methods of image processing and principles, which they are based on, are described. Methods for assessing cardiocyte contractility are also described. In the following part, chosen methods are implemented in MATLAB® and applied on two image sequences of cardiac cells, which were obtained using bright field microscopy.
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