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Multidimensional transfer functions for scalar volumetric data visualization
Mach, Pavel ; Kolomazník, Jan (advisor) ; Dupej, Ján (referee)
Direct volume rendering is an algorithm used for displaying three-dimensional scalar data, like image from Computed Tomography. This algorithm makes use of a concept of Transfer functions for assigning optical properties to the data values. We studied two dimensional transfer functions, that besides primary values have additional dataset as an input. In particular, we studied computation of this secondary dataset with respect to the primary image function shape. This was done by analysing eigenvalues of the Hessian matrix in each image point. We proposed one formula and implemented several others for computing the probability that image point belongs to the blood vessel. Powered by TCPDF (www.tcpdf.org)
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Haptic rendering for 6/3-DOF haptic devices
Kadleček, Petr ; Kmoch, Petr (advisor) ; Kolomazník, Jan (referee)
Application of haptic devices expanded to fields like virtual manufacturing, virtual assembly or medical simulations. Advances in development of haptic devices have resulted in a wide distribution of assymetric 6/3-DOF haptic devices. However, current haptic rendering algorithms work correctly only for symmetric devices. This thesis analyzes 3-DOF and 6-DOF haptic rendering algorithms and proposes an algorithm for 6/3-DOF haptic rendering involving pseudo-haptics. The 6/3-DOF haptic rendering algorithm is implemented based on the previous analysis and tested in a user study.
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Generic algorithms for polygonal mesh manipulation
Hmíra, Peter ; Kolomazník, Jan (advisor) ; Dupej, Ján (referee)
This bachelor thesis analyses algorithms working with the volume data, especially the triangle or polygon mesh. The results of the analysis are applied in the design of the generic library which can be templated with any implementa- tion of mesh satisfying requirements of the library. The library is written in C++ using the norm C++11 with assistance of the boost library. The choice of the programming language is supported by the strong emphasis on the run-time per- formance as well as the capabilities of C++ to analyze a templated code during the compile-time. Later in thesis is described the implemenation of the library, usage of the algorithms and their concepts, the purpose of the adapters - tools that allow to run algorithms over such an implementation of the mesh that is not properly designed for the algorithm. The technique used in the development of this library can be later applied in the library developement, thus adding new algorithms to the library.
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Recognition and Filtration of Unwanted Video-Sequences
Vlček, Jakub ; Surynek, Pavel (advisor) ; Kolomazník, Jan (referee)
The thesis deals with the possibilities of recognition video sequences and possibility of machine learning based on previous knowledge. I use neural networks which I learn on characteristics generated from images. Images are characterized using image functions like histogram and statistical functions such as mean and correlations to detect scenes in video-sequence. I used all of these findings to implement the demonstration program. The program can play video, display statistical information about the sequence or frame by frame and detect sequences similar to advertisements on the basis of statistical properties and respond to it by defined events.
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Dynamic simulation of rigid bodies using programmable GPUs
Cséfalvay, Szabolcs ; Kmoch, Petr (advisor) ; Kolomazník, Jan (referee)
The goal of this work is to create a program which simulates the dynamics of rigid bodies and their systems using GPGPU with an emphasis on speed and stability. The result is a physics engine that uses the CUDA architecture. It runs entirely on the GPU, handles collision detection, collision response and different forces like friction, gravity, contact forces, etc. It supports spheres, rods (which are similar to cylinders), springs, boxes and planes. It's also possible to construct compound objects by connecting basic primitives.
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Vessel segmentation
Dupej, Ján ; Pelikán, Josef (advisor) ; Kolomazník, Jan (referee)
Title: Vessel segmentation Author: Ján Dupej Department / Institute: Department of Software and Computer Science Education Supervisor of the master thesis: RNDr. Josef Pelikán, KSVI Abstract: In this thesis we researched some of the blood vessed segmentation and visualization techniques currently available for angiography on CT data. We then designed, implemented and tested a system that allows both semi-automatic and automatic vessel segmentation and visualization. For vessel segmantation and tracking we used a region-growing algorithm that we overhauled with several heuristics and combined with centerline detection. We then automated this algorithm by automatic seed generation. The visualization part is accomplished with an adaptation of the well-known straightened CPR method that we enhanced so that it visualizes the whole cross-section of the blood vessel, instead of just one line of it. Furthermore, we used the Bishop frame to maintain minimal twist of the curve-local coordinate system along the whole vessel. Keywords: vessel segmentation, medical data analysis, volume data
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Face Recognition in Social Networks
Mach, Pavel ; Skopal, Tomáš (advisor) ; Kolomazník, Jan (referee)
Popularity of face recognition in image galleries and social networks is growing. But none of these real world applications let the user adjust parameters. The goal of this thesis is to develop a library for face detection and recognition which can be easily used in some other program and also a web application recognizing faces, with environment similar to the one of social networks, which uses the library. Of course we do not try to compete with big social networks in the field of face recognition, because it will be almost impossible due to their enormous databases. In the experimental part of the work we try to find most suitable parameters such that face detection and face recognition would be as accurate as possible.
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Generování vlasů interpolací
Šik, Martin ; Křivánek, Jaroslav (advisor) ; Kolomazník, Jan (referee)
This thesis describes a procedural hair generator that is able to generate hair from just a few hairs, called hair guides, which are directly modeled by a 3d artist. The procedural hair generator is a part of Stubble project -- a tool for hair modeling in Autodesk Maya. The procedural hair generator can generate hair during rendering, thus avoiding storage of hair geometry in a scene file, which makes the rendering process very efficient. Furthermore, hair can be generated interactively and displayed by OpenGL during modeling in Maya. Generated hair geometry is mainly defined by interpolation from the mentioned hair guides; however it is also influenced by many hair properties. These properties can change hair geometry using noise functions, define hair color, width and more. To determine hair root positions on a given triangular mesh I use my own mesh sampling algorithm that generates random samples on a triangular mesh according to a density defined by a 2-dimensional texture. My sampling algorithm uses an innovative way of sampling from a discrete probability distribution, which can be used in other applications than mesh sampling.
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