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Magnetic resonance imaging via optimization methods
Onderlička, Tomáš ; Šorel,, Michal (referee) ; Rajmic, Pavel (advisor)
Magnetic resonance imaging is a diagnostic method to form images of the organs in the body. Long acquisition times are the main disadvantage, however it is possible to accelerate the data acquisition with the method of compressed sensing by sensing fewer samples and formulating an optimization method for image reconstruction. The aim of this thesis is to describe and compare the common optimization methods and to create a software capable of solving them. Another objective is to observe how much the data acquisition can be accelarated without the loss of image quality when dealing with real data. The most promising method in the experiment was total generalized variation (TGV) regularization which was able to reconstruct an image with a proper quality using only a quarter of the data.
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Web applications supporting education of JPEG compression
Dziuina, Valeriia ; Záviška, Pavel (referee) ; Rajmic, Pavel (advisor)
This bachelor thesis deals with the problem of lossy compression of image data implemented by the JPEG algorithm. The JPEG algorithm itself is described, as well as the background necessary for its understanding, such as the physical and physiological nature of colour formation, its basic parameters and RGB and YCbCr colour models. The result of this work is three web applications, each of which should demonstrate the flow of certain steps of the algorithm and their influence on the final image. These applications are first aimed at simplifying the understanding of the image data compression process within the JPEG algorithm.
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Identification of 3D objects for Robotic Applications
Hujňák, Jaroslav ; Návrat, Aleš (referee) ; Matoušek, Radomil (advisor)
This thesis focuses on robotic 3D vision for application in Bin Picking. The new method based on Conformal Geometric Algebra (CGA) is proposed and tested for identification of spheres in Pointclouds created with 3D scanner. The speed, precision and scalability of this method is compared to traditional descriptors based method. It is proved that CGA maintains the same precision as the traditional method in much shorter time. The CGA based approach seems promising for the use in the future of robotic 3D vision for identification and localization of spheres.
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Bin Picking and Robotic Vision
Múčka, Jan ; Parák, Roman (referee) ; Matoušek, Radomil (advisor)
The aim of this master’s thesis is to describe the Robotic Vision for Bin Picking usage and creating an application for the realization of this task. This application will be able to distinguish several objects based on data from a camera with deep perception and should find the location of object, recognize it and determine its location and orientation. Bin Picking is one of the biggest challenges in today's automation.
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Magnetic resonance imaging via optimization methods
Onderlička, Tomáš ; Šorel,, Michal (referee) ; Rajmic, Pavel (advisor)
Magnetic resonance imaging is a diagnostic method to form images of the organs in the body. Long acquisition times are the main disadvantage, however it is possible to accelerate the data acquisition with the method of compressed sensing by sensing fewer samples and formulating an optimization method for image reconstruction. The aim of this thesis is to describe and compare the common optimization methods and to create a software capable of solving them. Another objective is to observe how much the data acquisition can be accelarated without the loss of image quality when dealing with real data. The most promising method in the experiment was total generalized variation (TGV) regularization which was able to reconstruct an image with a proper quality using only a quarter of the data.
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Sampling Rate Conversion
Hylmar, Petr ; Vítek, Martin (referee) ; Kozumplík, Jiří (advisor)
This thesis is focused on sampling rate conversion by a rational factor interpolation and decimation and sampling rate coversion by an arbitrary factor interpolation and decimation. There are described methods sampling rate conversion in time domain based on lowpass FIR linear filter and in spectral domain based on zero spectral lines. These methods are created in Matlab programming and tested on particular example. The results of this thesis are sensible parameter lowpass FIR linear filter for sampling rate conversion and discussion success rate used methods.
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Fractional-Octave Analysis of Acoustic Signals
Ryšavý, Marek ; Frenštátský, Petr (referee) ; Schimmel, Jiří (advisor)
The diploma thesis is focused on design and optimalization of digital octave and fraction-octave band filters. This thesis describe the behavior of filters in systems with fixed point arithmetics and investigate the impact of quantization coefficients for frequency response of filter. Filters, whitch has been designed, are implemented into simple software in C. Designed filters are in accordance with standard IEC 61260.
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Modern Methods of Realistic Lighting in Real Time
Szentandrási, István ; Pečiva, Jan (referee) ; Herout, Adam (advisor)
Fyzikálně přijatelné osvětlení v reálném čase je často dosaženo použitím aproximací. Současné metody často aproximují globální osvětlení v prostoru obrazu s využitím schopností moderních grafických karet. Dva techniky z této kategorie, screen-space ambient occlusion a screen-space directional occlusion jsou popsány detailněji v této práci. Screen-space directional occlusion je zobecněná verze screen-space ambient occlusion s podporou jednoho difúzního odrazu a závislostí na směrové informaci světla. Hlavním cílem projektu bylo experimentování s těmito metodami. Pro uniformní distribuci náhodných vzorek pro obě metody byla použita Halton sekvence. Pro potlačení šumu je použita bilaterální filtrace, která bere do úvahy geometrické vlastnosti scény. Metody jsou dál zrychleny použitím nižších rozlišení pro výpočet. Rekonstrukce výsledků do původní velikosti pro vytvoření konečného obrazu je realizována pomoci joint bilateral upsamplingu. Kromě metod globálního osvětlení byly v práci použity aj metody pro mapování stínů a HDR osvětlení.
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Advanced Algorithms for Satellite Communication Signal Processing
Záplata, Filip ; Bezoušek, Pavel (referee) ; Šimša, Jan (referee) ; Kasal, Miroslav (advisor)
Dizertační práce je zaměřena na softwarově definované přijímače určené k úzkopásmové družicové komunikaci. Komunikační kanály družicových spojů zahrnujících komunikaci s hlubokým vesmírem jsou zatíženy vysokými úrovněmi šumu, typicky modelovaného AWGN, a silným Dopplerovým posuvem signálu způsobeným mimořádnou rychlostí pohybu objektu. Dizertační práce představuje možné postupy řešení výpočetně efektivní digitální downkonverze úzkopásmových signálů a systému odhadu kmitočtu nosné úzkopásmových signálů zatížených Dopplerovým posuvem v řádu násobků šířky pásma signálu. Popis navrhovaných algoritmů zahrnuje analytický postup jejich vývoje a tam, kde je to možné, i analytické hodnocení jejich chování. Algoritmy jsou modelovány v prostředí MATLAB Simulink a tyto modely jsou využity pro ověření vlastností simulacemi. Modely byly také využity k experimentálním testům na reálném signálu přijatém z družice PSAT v laboratoři experimentálních družic na ústavu radioelektroniky.
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Front end for software receiver
Slezák, Jakub ; Horský, Pavel (referee) ; Šrámek, Petr (advisor)
This thesis deals with a theoretical analysis of the basic parameters of receivers, input circuit architecture and signal digitization. According to the specified assignment it is outlined block scheme of front end for software receiver with specified components and the total bilance is calculated. Individual parts of the system are designed and realized. This is a set of four input filters for bandwidths: short waves up to 30 MHz, 87,5-108 MHz, 144-148 MHz and 174-230 MHz. The main point of design is a circuit containing a low-noise amplifiers, switches, and two amplifiers with adjustable amplification. Mainly are used integrated circuits from Analog Devices corporation. To control the various switches and adjustable amplifiers was designed a separate panel, which is connected to the main circuit via a cable. In the last phase was the whole system and its components subjected to measurements. Thanks to a number of mounted SMA connectors it is possible to measure different parts of the system and we are able to modify it partially.
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