|
|
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)
|
|
|
Segmentation and density estimation in femur
Horáček, Jan ; Maršálek, Lukáš (advisor)
Title: Segmentation and Density Estimation in Femur Author: Jan Horáček Department: Department of Software and Computer Science Education Supervisor: Mgr. Lukáš Maršálek Supervisor's e-mail address: lukas.marsalek@mff.cuni.cz Abstract: There are two basic ways of surgical treatment of femoral neck frac- ture - total endoprosthesis or a special metal screw in the bone. In case of a dense enough bone the screws are preferred. But for a too sparse bone, the screw may cut through the femoral head, which results in further surgical operations. We present a novel method for femoral head density measurement, which serves as another hint for the doctor's decision, whether to apply a screw or total endo- prosthesis. Our approach is based on semi-automatical femoral head segmenta- tion from CT dataset based on finding optimal path through polar coordinates on axial slices. The cost function is based on a combination of corticallis proper- ties, mostly the directional behavior of 3D gradients and their size in 2D slices, where they form typical "channels". The final volume is computed using filling and morphological algorithms and its properties are further measured. The final implementation was experimentally validated on RTG clinic of Bulovka hospital and allows radiologists to intuitively and accurately estimate...
|
|
|
Vektorová segmentace objemových medicínských dat založená na Delaunay triangulaci
Španěl, Michal ; Martišek, Dalibor (referee) ; Sochor, Jiří (referee) ; Kršek, Přemysl (advisor)
Image segmentation plays an important role in medical image analysis. Many segmentation algorithms exist. Most of them produce data which are more or less not suitable for further surface extraction and anatomical modeling of human tissues. In this thesis, a novel segmentation technique based on the 3D Delaunay triangulation is proposed. A modified variational tetrahedral meshing approach is used to adapt a tetrahedral mesh to the underlying CT volumetric data, so that image edges are well approximated in the mesh. In order to classify tetrahedra into regions/tissues whose characteristics are similar, three different clustering schemes are presented. Finally, several methods for improving quality of the mesh and its adaptation to the image structure are also discussed.
|
|
|
Java Client for 3D Displaing of Medical Image Data
Bireš, Jiří ; Štancl, Vít (referee) ; Kršek, Přemysl (advisor)
The thesis considers use of Java language in interactive 3D displaying of medical image data. Main point is to find out advantages of using this language in medical visualisations and find suitable tools for its future usage. At the conclusion it evaluates advantages and disadvantages of used technologies and suggests possible development of the appliacation
|
|
|
Visualization of Marked Cells of a Model Organism
Kubíček, Radek ; Kršek, Přemysl (referee) ; Herout, Adam (advisor)
This master thesis is focused on volumetric data rendering and on highlighting and visualization of the selected cells of the model organisms. These data are captured by a confocal deconvolution microscope. Input data form one large volumetric block containing separate slices. This data block is rendered by an applicable method and then are identified and visualized the cells marked by the GFP (Green Fluorescent Protein) process or by chlorophyle fluorescency. The principal aim of this work is to find out the preferably optimal effective method enabling this highlighting, most preferably working without a manual check. Due to the data structure, this ambition seems hardly realizable, so it suffices to find out a manual working method. The last step is to embed the results of this work into FluorCam application, the confocal deconvolution microscope data visualizer.
|
|
|
Realistic Rendering of Smoke and Clouds
Kopidol, Jan ; Žák, Pavel (referee) ; Jošth, Radovan (advisor)
This work discourses about methods of rendering volumetric data such as clouds or smoke in computer graphics and implementation of this feature to existing application. The first part is summary of techniques and tricks used in computer graphics to display such objects in scene, their pros and cons and the most used techniques of displaying volumetric data. Next part is more closely focused to choosed technique of rendering volumetric data with consideration of light behavior inside the volume (also called participating media) and basic relationships used used in computation. In following part of work there is short list of applications - renderers used to realistic rendering of scene, which are suitable for implementation of selected volumetric data rendering algorithm. Selected application - Blender is describled more deeply including its inner structure, especially rendering engine. Last part of work is dedicated to design, implementation and integration of rendering algorithm itself.
|
|
|
Image Processing on GPUs
Bačík, Ladislav ; Španěl, Michal (referee) ; Smrž, Pavel (advisor)
This master thesis deals with modern technologies in graphic hardware and using their for general purpose computing. It is primary focused on architecture of unified processors and algorithm implementation via CUDA programming interface. Thesis base is to choose suited algorithm for GPU horsepower demonstration. Main aim of this work is implementation of multiplatform library offering algorithms for discrete volumetric data vectorization. For this purpose was chosen algorithm Marching cubes that is able to find surface of processed object. In created library will be contained algorithm runnable on graphic device and also one runnable on CPU. Finally we compare both variants and discuss their pros and cons.
|
|
|
Endless Cave
Pospíšil, Petr ; Pečiva, Jan (referee) ; Milet, Tomáš (advisor)
The goal of this thesis is to implement an application showing an endless cave. The basis of this cave is simplex noise method. On the noise produced by this function is afterwards applied thresholding. Produced grid of points is used like input for marching tetrahedrons algorithm. This algorithm converts volumetric data to boundary representation. Phong reflection model and Bump mapping were used in the application, too, in order to improve the visual quality. The application is based on OpenGL library. The first part of the technical report contains theoretical description of mentioned methods, the second part contains description of implementation.
|
guest ::
