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Ultrasound image registration based on active contours
Hesko, Branislav ; Jakubíček, Roman (referee) ; Harabiš, Vratislav (advisor)
This diploma thesis aims to implement an active contour method for ultrasound image segmentation. Properties of ultrasound images, basic segmentation approaches and a~principle of choosen active contour methods are described within theoretical part. Two different groups of active contour methods exists, methods with use of gradient and without use of gradient as image feature. For comparision, one method of each group is implemented in practical part and subsequently, segmentation efficiency and properties of methods are compared in evaluation part.
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Specle analysis for optical coherence tomography image segmentation
Gallo, Vladimír ; Kolář, Radim (referee) ; Štohanzlová, Petra (advisor)
This paper presents basic principles of optical coherence tomography, review of applications and basic categorization of these systems. Paper also deals with the typical properties of images from optical coherence tomography, especially speckle pattern. This paper also provides an overview of the origin of speckle noise and utilization of its dependence on microstructure of probed tissue for image classification based on textural analysis. Experimental part of this paper consists of phantom preparation, data acquisition by OCT system, implementation of speckle analysis in MATLAB and of testing of its functionality on standard textural dataset and also on acquired image phantom data. Speckle analysis is used for phantom image data segmentation.
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Image processing of data from the ultrasound system GE VingMed System Five
Pokorný, Pavel ; Mézl, Martin (referee) ; Harabiš, Vratislav (advisor)
The master thesis is focused on the principle of ultrasonographs and their modes, and ways of denoising data obtained by ultrasonographs. This project will also concentrate on removing the speckle noise, because the speckle noise has the largest share of the noise in the measured data in ultrasonographs. The other main objective was to describe advanced methods of filtration, especially the modifications of the median filter, such as the modified hybrid median filter and modification of the anisotropic diffusion, namely generalizing Perona-Malik anisotropic diffusion using restricted dissimilarity functions. These two filters were tested on images with artificial noise and on data captured using the ultrasound system GE VingMed System FiVe. Also, the program for filtering and display filtered ultrasound data captured by GE VingMed System FiVe is described.
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Speckle noise suppression methods in ultrasound images
Teplý, Lukáš ; Harabiš, Vratislav (referee) ; Mézl, Martin (advisor)
Ultrasound investigation is one of meaningful imaging at present. Advantages of ultrasound are, that it hasn´t side effects as a rtg radiation and it is noninvasive. Ultrasound diagnostic is exploited in all branch of medicine (urology, cardiology, orthopeadist, gynecology etc.) to display organs, tissues and cavities of the human body. We use display in 2D, 3D and most modern display in 4D. We can encounter with many kinds of artifact. Artifacts are described more closely at 3rd chapter. Speckle noise deteriorates informative yiled of ultrasound picture. We try to remove speckle noise by simpler methods or more complex methods of filtration. These methods are described at 5th chapter. Programme for speckle filtering from pictures is part of this master´s thesis.
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Speckle noise suppression methods in ultrasound images
Tvarůžek, Marek ; Harabiš, Vratislav (referee) ; Mézl, Martin (advisor)
This diploma thesis deals with the methods of despeckling in ultrasound images. Ultrasound imaging and related artifacts are described in more details. Ultrasound imaging has its pros and cons, where speckle noise is a disadvantage to be solved. Models of origin of this specific noise are referred too. Practical part of this thesis aims on filtering speckled images by basic and advanced filtering methods as are linear filtering, median filtering, application of Frost filter, QGDCT, geometric filtering, anisotropic diffusion filtering and filtering based on wavelet transformation. Results are compared on the basis of objective criteria.
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Optical methods in non-contact velocity measurement
Šmíd, Petr
The paper presents an overview of some interesting methods using optical and sound waves for non-contact velocity measurements. The paper focuses mainly on optical techniques using different optical principles as interferometry, image analysis and processing, and speckle effect.
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Optical methods in experimental mechanics
Hrabovský, Miroslav
The paper deals with experimental methods used in experimental mechanics, especially in experimental stress analysis. High attention is given to optical methods - classical and modern optical methods and its future in mechanics. They are classical interferometry based on optical interference and superposition, stereometry, photoplasticity, moiré, holography speckle photography etc.
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