Rastrové algoritmy pro výpočet izočar

Příspěvek obsahuje popis několika algoritmů pro výpočet izočar v prostředí rastrového výstupního zařízeni. Algoritmy byly vyvinuty na základě praktických požadavků při zobrazováni naměřených dat v hyd-robiologii. Základními požadavky byla univerzálnost použití, velká rychlost výpočtu a velká přesnost. Byly vyzkoušeny dva principy výpočtu: rekurzivní dělení oblasti a trasováni jednotlivých izočar, hledání izočar se provádí rekurzivnim dělením. Algoritmy dosahují velké přesnosti, chyba je srovnatelná s velikosti rastru. Příspěvek obsahuje kromě popisu jednotlivých algoritmů i diskusi o jejich rychlosti a možnostech dalšího vylepšení

Endogenní vměstky v oceli a jejich detekce defektoskopickými zkouškami u odlitků

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta metalurgie a materiálového inženýrství. Katedra (632) slévárenstv

Parallel radiosity on a cluster of workstations

A parallel version of progressive refinement radiosity with radiosity overshooting and adaptive surface subdivision is presented. A cluster of workstations under the operating system UNIX was chosen as parallel hardware. The whole system was organized according to the master-worker paradigm. We investigated how to adjust algorithms for run-time adaptive surface subdivision and overshooting for such parallel hardware, especially if we use a relatively slow computer network or, moreover, a network with highly varying throughput. Variation in computer performance (including the possibility that some workstations might crash) was also considered

JaGrLib: library for computer graphics education

This article describes JaGrLib – environment for experimenting with algorithms, data structures, general approaches and implementation patterns. This framework was primarily developed to help teaching of computer graphics at Charles University in Prague. But it can be used as a handy tool for experimenting in any branch of applied computer science where modularity, versatility and reusability are key features. The system is implemented in Java language and takes advantage of its object-oriented design, good portability, exibility, etc. At the end of 2003 a new graphical environment was developed and the whole library is publicly available with dozen of modules – mainly from eld of computer graphics

Aplikace metod postupných profilových průtoků pro vyhodnocení základního odtoku na malých povodích

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Duct tracking in 3D medical data

Implementing duct tracking of bronchi and blood vessels in 3D medical data can significantly help in examining these body structures and reduce time needed for correct diagnosis. Nature of the problem involved may require some operator interaction when selecting duct branches of interest or correcting possible mistakes in duct path segmentation. Noise, badly discernible duct walls, branching or extreme duct curvatures, that can be found in computer tomography data, make the segmentation challenging. There are more ways to display segmented ducts, as overlay over original data or unrolled to planar tube, allowing easier measurements of length, width or observation of tube anomalies

Measuring and segmentation in CT data using deformable models

We investigated the concepts, strategies, and functions of a 3D virtual design environment for collaborative, real-time architectural design using our 3D comparative navigation system and virtual reality technology. The development of the ‘comparison’ concept has enabled interactive design in real time in a 3D computer environment. Since participants must be able to easily understand the proposed design systems that help them gain this understanding are required. While comparison is an effective way to gain such an understanding, comparing one proposed design to another using existing systems is difficult because the user must operate their viewpoints separately. We therefore created a prototype system that displays different contents simultaneously while controlling the viewpoints automatically to facilitate content comparison. This comparative navigation system facilitates comparison of proposed designs by displaying related parts of the designs automatically. In this paper, we describe the concepts, strategies, and functions of a 3D virtual design environment for collaborative, real-time architectural design that is based on our 3D comparative navigation system and real-time simulation technology. We also evaluate the advantages and disadvantages of using this design environment for collaborative architectural design