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Java applets for image processing
Čišecký, Roman ; Číka, Petr (referee) ; Šmirg, Ondřej (advisor)
The bachelor´s thesis is concerned with image processing techniques such as calculating his-togram and its equalization, image filtering in frequency and time domain, creating panoramic pictures and creating a disparity map This thesis describes the various methods of image processing and their use in practice. The last part deals with creating particular applications for image processing and its transformation to applets executable on the web.
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Implementation of edge detector using wavelet transform
Pálka, Zbyněk ; Rášo, Ondřej (referee) ; Růčka, Lukáš (advisor)
This thesis is focused on edge detection in image. In theoretical part are contained genarally used methods of edge detection using first and second-order derivate and both of mentioned methods are described here. Further it’s deiscribed here continuous, descrete and two dimensional descrete wavelet transform and process of noise removing in image by descrete wavelet transform. In next part are analysed two methods of edge detection using wavelet transform and their possible realizations in program Matlab. In practical part of thesis is in detail described algorithm of program on edge detection using wavelet transform and it‘s described here individual functions of program. The main content of practical part are visual results of wavelet edge detector and their comparison with Canny, Prewitt and Sobel edge detector.
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Numerical image processing methods for rotating condenser microscope images processing
Týč, Matěj ; Martišek, Dalibor (referee) ; Druckmüller, Miloslav (advisor)
Tato práce popisuje vznik obrazu v transmisním světelném mikroskopu s proměnnou aperturou kondenzoru. Tento způsob pořizování obrazu je výhodný při pozorování tlustých vzorků, což jsou objekty, u kterých je v mikroskopickém měřítku významná výška. Klasické transmisní mikroskopy pro tento výzkum vhodné nejsou, protože výsledný obraz, který produkují, obsahuje patrné informace z velkého objemu vzorku mimo oblast, která je vyšetřovaná. Tento problém byl vyřešen po vynálezu konfokálního mikroskopu, který je ovšem daleko dražší a má i některé nevýhody navíc. Cílem je zpracovat obrazy pořízené pomocí kondenzoru s rotující aperturou tak, aby došlo k redukci podílu nežádoucí informace a obraz se tak stal "čistším". Tato metoda zpracování obrazu nemohla být použita v minulosti, protože tehdejší počítače neměly dostatečnou paměť a výkon. Na tuto metodu se dá nahlížet jako na převod množiny výstupů z mikroskopu s vylepšenou osvětlovací soustavou na odpovídající množinu výstupů konfokálního mikroskopu.
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Presentation of selected themes of BSIS in PPT-environment
Havlín, Radomil ; Šebesta, Vladimír (referee) ; Sigmund, Milan (advisor)
The bachelors thesis occupy by topics of the course BSIS, which can be presented by the multimedia and animation techniques in the presentation. In the introduction, these topics are given a different method of processing. In most cases, provides a modular solution by demonstration and argued spectrum signal. The chapters describe the operation with one, two signals at the time, the properties of Fourier transform with illustrative demonstration, the correlation with convolution, kvaziperiodické signals and the last chapter the spectrum of selective signals.
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Multimedia support of the course BSIS
Pasečný, Jan ; Šebesta, Vladimír (referee) ; Sigmund, Milan (advisor)
This paper takes aim at creating a consistent form of study materials, supplemented with illustrative examples, for Signals and systems subject. The thesis starts with basic characteristics of acoustic, image, biological and communication signals. Characteristics of linear signals and AD&DA conversion has been added to the next part and to complete the submission, discrete signals follow. Diploma thesis as a whole contains basic theoretical description of problematics, which it tries to supplement with interesting examples, connections, graphs and matlab scripts for illustrative presentation of mentioned problematics.
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Multichannel Image Deconvolution
Bradáč, Pavel ; Kolář, Radim (referee) ; Jiřík, Radovan (advisor)
This Master Thesis deals with image restoration using deconvolution. The terms introducing into deconvolution theory like two-dimensional signal, distortion model, noise and convolution are explained in the first part of thesis. The second part deals with deconvolution methods via utilization of the Bayes approach which is based on the probability principle. The third part is focused on the Alternating Minimization Algorithm for Multichannel Blind Deconvolution. At the end this algorithm is written in Matlab with utilization of the NAG C Library. Then comparison of different optimization methods follows (simplex, steepest descent, quasi-Newton), regularization forms (Tichonov, Total Variation) and other parameters used by this deconvolution algorithm.
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Correction of phase image background in the digital holographic microscope using convolution
Rudolfová, Zdena ; Malina, Radomír (referee) ; Uhlířová, Hana (advisor)
This bachelor thesis concentrates on a correction of background in the phase image of cells from a transmitted-light digital holographic microscope (TDHM). Optical aberrations in the optical systems of the object and reference arms cause "deformation" of the phase image. The cell is not displayed on a background with a constant value of phase, it is displayed on a background with phase values continuously changing between different places in the image. A method for removing the consequence of this imperfection from the image is described in this thesis. The principle lies in partial convolution of the phase image with a convolution kernel determined by a two-dimensional Gaussian function with the same variance in the both axes. To eliminate loss of information about the cells, the convolution is computed only from those parts of the phase image which contain no cells. The result of the convolution is considered to be an approximation of the background. This approximation is then subtracted from the phase image. The resulting phase image has a constant background, containing only noise. The necessary mathematical concepts are resumed in the introductory part of the thesis. The basic principle of the TDHM image reconstruction is also described. As a part of the thesis, a computer programme Odečet pozadí (Background subtraction) was created, which processes the phase images from the TDHM using this method.
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Convolution Model of Time-activity Curves in Blind Source Separation
Tichý, Ondřej ; Šmídl, Václav
Availability of input and organ functions is a prerequisite for analysis of dynamic image sequences in scintigraphy and positron emission tomography (PET) via kinetic models. In PET, the input function can be directly measured by sampling the arterial blood. This invasive procedure can be substituted by extraction of the input function from the observed images. Standard procedure for the extraction is based on manual selection of a region of interest (ROI) which is user-dependent and inaccurate. The aim of our contribution is to demonstrate a new procedure for simultaneous estimation of the input and organ functions from the observed image sequence. We design a mathematical model that integrates all common assumption of the domain, including convolution of the input function and tissue-specific kernels. The input function as well as the kernel parameters are considered to be unknown. They are estimated from the observed images using the Variational Bayes method.
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