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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A Collaborative VolumeViewer

Palmberg, Staffan, Ranlöf, Magnus January 2002 (has links)
This study has been carried out as a part of the EC funded project, SMARTDOC IST-2000-28137, with the objective of developing application components that provide highly interactive visualization and collaboration functionalities. The low-level components from the graphics library AVS OpenViz 2.0 are used as the development basis. The application components can be inserted into electronic documents that allow embedded controls such as web documents or Microsoft Word or PowerPoint documents. Instead of displaying results as static images, a SMARTDOC component provides the ability to visualize data and interact with it inside the document. Although the principal goal of the SMARTDOC project is to create components in a number of different application domains this study concentrates on developing a medical imaging application component in collaboration with the project partners AETmed and professor Alan Jackson at the University of Manchester. By incorporating the application component into patient reports, the clinicians are provided the ability to interact with the 3D data that is described in the reports. To improve the usability of the component, it makes use of a visual user interface (VUI), which gives the user the ability to interact and change parameters directly in the visualization process. Collaborative work over geographical distances is an area that is becoming increasingly common and thus more interesting. As the availability of bandwidth has increased and the communication technologies have advanced, many companies express their interest for this new practical method of work. A company with offices in different countries would benefit from collaborative techniques providing closer cooperation within the company. Specialized institutions and laboratories could gather much experience and information through collaborative research. Medical imaging and visualization technique are areas where distinct disciplines such as networking, user interfaces and 3D visualization naturally can be fused together in order to develop collaborative environments. The visualization components developed within the SMARTDOC project will be the foundation for collaborative application components integrated with the Microsoft DirectX® multimedia library. In the medical imaging area, collaborative work can be used to improve diagnoses, journaling and teaching. This study focuses on developing a prototype of an interactive visualization component for 3D medical imaging and creating a collaborative environment using a multimedia library originally meant for network gaming.
22

Interaktivní Java applet pro 3D vizualizaci optického disku oka / Interactive Java applet used for 3D optic nerve head visualization

Šikl, Jaroslav January 2010 (has links)
The aim of this thesis was to design and implement the interactive Java applet used for topography 3D optic nerve head visualization. Primary purpose of the 3D vizualization is ophthalmology, especially for diagnosis of glaucoma. More over should serve as a training material, which enables to study the transformation of 2D figures to 3D model and to test the effects of adjustments and regulations to imaging of the model in 3D space. Two program versions were designed in this work using the development system NetBeans version 5.5. Their final realization is implemented as .html application working in web browser window. First version of the designed applet is simple intuitive application with several default settings, so that the figure is opened automatically to 3D model. Subsequently, the applet enables to set the size of the image, 3D depth of the image, smoothing of the surface and selection of monochrome or coloured image. The second version is the extension of the first version of the designed applet, and provides the possibility to display x, y, z axis, depiction of the 3D model surface by dots, curves or grid, and illumination of the surface. Software was tested on available topographic data acquired by HRT equipment and in different web browsers. Technical documentation and user’s manual are also involved in this thesis.
23

Vizualizace programového toku spustitelných souborů / Visualization of Program Flow of Executable Files

Rusnák, Jakub January 2011 (has links)
This master's thesis describes the visualization of program flow of executable files on Microsoft Windows platform. In theoretical part it describes the PE EXE file format and instruction format. In following chapters there are described current methods of malware analysis, especially the analysis of program flow. Then there are introduced current malware visualization methods and tools for 3D data visualization. The main objective is design and implementation of 3D visualization of jumps in executable files. The result is the visualization tool, which helps to identify different samples of malware from the normal code.
24

3D-visualisering för stadstrafikplanering : En datateknisk konstruktion och analys

Tanda, Cristoffer January 2020 (has links)
För att kunna kommunicera idéer relaterat till urbana projekt så behövs verktyg för att kunna framföra detta i en visuell miljö på ett sätt som människor från många olika fält kan förstå. Digitala 3D-miljöer är därmed något som efterfrågas allt mer. För att bygga ett sådant verktyg så finns licensierade teknologier, men dessa verktyg kommer med en ekonomisk implikation. Rapporten undersöker om det är möjligt att bygga en applikation för att kunna representera stadstrafik i en 3D-visualiseringsmiljö från grunden, utan att använda externa licenser eller bibliotek i den mån som är möjligt. En applikation som håller en prestanda som gör det möjligt att interagera med i realtid och som har möjlighet att representera en stad från verkligheten. Detta utforskas genom att endast använda Direct3D tillsammans med C++. Analys av 3D-visualisering ställs mot ett tidigare forskningsarbete av Carnegie Mellon University. Mjukvaruarkitektur och prestanda är delar som också har analyserats under utvecklingen. En stor del av projektet vilar på implementationsdelen, där en arkitektur som innefattar grafikrendering, simulering och en allmän programstruktur har utvecklats. Arbetet resulterade i en applikation som kan visualisera en stadsmiljö i 3D, med en trafiksimulering som kan representera över 100 000 fordon, med en prestanda som gör det möjligt att interagera med i realtid. Det konstaterades att applikationen fungerar som en grund att utveckla vidare på, baserat på de parametrar som sattes upp för projektet. För att öka förståelsen kan det finnas en fördel med att ha en 3D-visualisering med en representation som inte helt avspeglar verkligheten, men som ändå har en tillräcklig koppling för att kunna vara ett användbart verktyg för kommunikation av idéer. / To communicate ideas related to urban projects, tools are needed, to be able to convey this in a visual environment. This must also be done in a way that people from many different fields can understand. Digital 3D environments are thus something that is increasingly in demand. To build such a tool there are licensed technologies, but these tools also come with a financial implication. The report investigates whether it is possible to build an 3D visualized application to represent a city with simulated traffic from scratch, without using external licenses or libraries to the extent possible. An application that keeps a performance level that allows it to be interactable in real time and that can represent a city from the real world. This is explored by using only Direct3D with C++. Analysis of the 3D visualization is compared to a previous research work by Carnegie Mellon University. Software architecture and performance are parts that have also been analysed during development. A large part of the project rests on the implementation part, where an architecture that includes graphics rendering, simulation and a general program structure has been developed. The work resulted in an application that can visualize an urban environment in 3D, with a traffic simulation that can represent over 100,000 vehicles simultaneously, with a performance that makes interaction in real time possible. It was found that the application can serve as a basis for further development, based on the parameters set for this project. To increase the understanding there may be an advantage of having a 3D visualization with a representation that does not fully reflect the real world, but which still has a sufficient connection to be a useful tool for communication of ideas.
25

VITASCOPE: Extensible and Scalable 3D Visualization of Simulated Construction Operations

Kamat, Vineet Rajendra 21 April 2003 (has links)
In the domain of operations design and analysis, the ability to see a 3D animation of processes that have been simulated allows for three very important things: 1) The developer of a simulation model can ascertain that there are no errors in the coding (Verification); 2) The experts, field personnel, and decision makers can discover differences between the way they understand the operation and the way the model developer understands it (Validation); and 3) A model can be communicated effectively which, coupled with verification and validation, makes it "credible" and thus used in making decisions. In the case of simulated construction operations, the existent body of knowledge and understanding did not generally permit modeled processes to be accurately visualized in 3D. The purpose of this research was to remedy this situation and find methods of describing animated 3D worlds that show how construction operations modeled using Discrete-Event Simulation were/can be carried out, using simple text statements and references to 3D CAD drawings. The fundamental question the work addressed was how to achieve accurate, dynamic, smooth, and continuous 3D animation of arbitrarily-complex simulated construction processes, based on meager pieces of operational information that can only be communicated when discrete events occur in simulation runs. The end result of this effort is VITASCOPE, an acronym for VIsualizaTion of Simulated Construction OPErations. VITASCOPE is a simple, parametric-text animation description language that is meant to be written out by end-user programmable software such as discrete-event simulation tools. Sequential instructions written in this language allow a computer to create a 3D virtual world that is accurate in time, space, and appearance; and that shows people, machines, and materials interacting as they build constructed facilities. / Ph. D.
26

3D-visualisering i mark- och anläggningsprojekt. : En studie utifrån Veidekkes förutsättningar att implementera 3D-modeller i produktion.

Radtke, Oliver, Kellgren, Markus January 2019 (has links)
Samhällsdigitaliseringen har lett till att byggbranschen mer och mer strävar efter att digitalisera verktyg och arbetssätt. Att presentera projekt i 3D har därför blivit ett hett ämne där flera aktörer strävar efter att både projektera och nyttja 3D ute i produktionen. Tidigare forskning inom ämnet har till största del valt att lägga fokus på byggskedet och belyser de fördelar som går att utvinna genom nyttjandet av så kallade VDC- eller BIM verktyg. Samtidigt belyser andra vetenskapliga rapporter mark och anläggning som ett betydelsefullt skede inom hela byggprocessen. Ett flertal menar också att mark- och anläggningsskedet spelar en huvudroll i huruvida ett byggprojekt når framgång eller inte. Med detta i åtanke upplever författarna att 3D-modeller i mark- och anläggningsprojekt inte utforskats till den grad som känns nödvändig för att belysa fördelarna, men även de olika hinder som står i vägen för en lyckad implementeringsprocess. Det råder inte heller några tvivel om att byggskedet kommit längre i digitala utvecklingsaspekter, så som att visualisera projekt i 3D, vid en jämförelse med mark och anläggning. I denna studie belyser därför författarna de fördelar som går att utvinna genom att visualisera mark- och anläggningsprojekt i 3D. Studien visar upp bevis på varför verktyget bör implementeras och vad aktörer bör tänka på vid en eventuell implementering av 3Dvisualisering i projekt. Syftet med studien är därav att utreda hur det undersökta fallföretaget kan integrera 3D-modeller i mark- och anläggningsprojekt, samt belysa vilka krav fallföretagets anställda ställer på en 3D-modell för att främja utvecklingen av ett verktyg som passar och leder till en hög nyttjandegrad ute i produktionen. Vidare sker en identifiering av vilka förutsättningar ute i mark och anläggningsprojekt som spelar en nyckelroll i huruvida en implementerad 3D-modell skall kunna figurera och verka så som det är tänkt. Studien utförs med en kvalitativ metod där granskning av befintlig litteratur lyfter fram de problemområden som författarna identifierat. Vidare utförs semistrukturerade intervjuer med tjänstemän och yrkesarbetare på fallföretaget Veidekke Entreprenad AB. Intervjuerna genomförs i syfte att identifiera aktuella problem ute i produktionen, undersöka respondenternas syn på 3D-modeller samt belysa verktygets potentiella inverkan på deras vardagliga arbete.  En tydligt övergripande slutsats är att 3D-modeller i allra högsta grad behövs ute i produktionen på mark- och anläggningsprojekt. Mycket pekar på att verktyget bland annat skulle bidra med en ökad förståelse kring utförandet av projekten, men också förbättra kommunikation och produktionsledande. Verktyget kan också enligt studien minimera problemområden gällande tekniska lösningar, förbättra planering, samt genom att digitalisera moment även tillfredsställa arbetsglädjen för produktionsteamet. / Due to the digitalization the construction business is increasingly striving against more digitized tools and working methods. Presenting projects in 3D has therefore become a hot topic where several actors are trying to implement 3D not only in the design phase but also in the production phase. Earlier research dealing with the subject largely chooses to focus on the building construction process and highlights the advantages that can be extracted using so called VDC- or BIM tools. Some of the scientific reports reviewed during this study on the other hand, highlights the importance of the infrastructure and earthworks stages as a part of the entire construction process. Many also believe that the infrastructure and earthworks stage play a key role in whether a construction project achieve success or not. With that in mind, the authors feel that 3D-models for infrastructure and earthworks, have not yet been explored to the extent that feels necessary, meaning that the advantages and the various obstacles that stand in the way of a successful implementation process needs to be investigated. There is no doubt that building construction has come further in a digital development aspect of visualizing projects in 3D, compared to infrastructure and earthworks. In this study the authors have highlighted the benefits that can be gained by visualizing infrastructure and earthworks projects in 3D. The study also shows evidence of why the application of such should take place and what companies should be considering when implementing 3D visualization into such projects. The purpose of the study is therefore to investigate how the company researched by the authors can integrate 3D models into their infrastructure and earthworks projects. This in addition to identifying the requirements that the employees have on a 3D model to facilitate development of a tool that fulfils these requirements and is usable in production. In addition, the conditions and requirements that play a main role in infrastructure and earthworks projects have been investigated to identify the most suitable conditions to allow the model to work in the most efficient way as possible. The study is conducted with a qualitative method including an examination of existing literature that highlights the problem areas identified by the authors. In addition, semi structured interviews are carried out with employees from the work-site leadership and the skilled workers at the company Veidekke Entreprenad AB. This to identify the current problem areas in the production of infrastructure and earthworks projects and to examine employees’ view about how 3D models would impact on their everyday work. A clear overall conclusion is that 3D-models are truly needed in infrastructure and earthworks projects out in production. A lot of factors indicate that the tool would, among other things, contribute to an increased understanding of the scope of projects and thus contribute to an improved communication and production process leading. Such a tool can according to this study, also minimize problem areas regarding technical solutions, contribute to a better planning, and by digitizing processes, increase job satisfaction for the site team.
27

Visualizador 3D baseado em head tracking e estereoscopia para aplicações com o método dos elementos finitos. / 3D viewer based on head tracking and stereoscopic for finite element method applications.

Junqueira, Luiz Antonio Custódio Manganelli 06 December 2013 (has links)
A visualização 3D de simulações pelo Método dos Elementos Finitos (MEF) ainda é uma experiência limitada em função da falta de realismo 3D nos monitores disponíveis. Além do monitor 3D realista, a melhor visualização destas simulações depende de uma apresentação MEF desenvolvida adequadamente, de forma a tirar maior proveito deste realismo 3D. Neste trabalho, é realizado o desenvolvimento de um visualizador MEF 3D, que reproduz os efeitos estereoscópicos e de rastreamento de cabeça (head-tracking), explorando melhor as percepções de profundidade com hardware acessível e bibliotecas gráficas utilizadas em aplicações convencionais. / The 3D visualization of Finite Element Method (FEM) simulations is still a limited experience due to the lack of realism of 3D monitors available. In addition to the realistic 3D monitor, better visualization of these simulations depends on a MEF presentation properly developed in order to get the most out of 3D realism. In this work, a 3D MEF viewer is develop, including stereoscopy and head tracking 3D effects, that better explores human depth cues using hardware from cost and benefit perspective and graphics libraries used in conventional applications.
28

Visualizador 3D baseado em head tracking e estereoscopia para aplicações com o método dos elementos finitos. / 3D viewer based on head tracking and stereoscopic for finite element method applications.

Luiz Antonio Custódio Manganelli Junqueira 06 December 2013 (has links)
A visualização 3D de simulações pelo Método dos Elementos Finitos (MEF) ainda é uma experiência limitada em função da falta de realismo 3D nos monitores disponíveis. Além do monitor 3D realista, a melhor visualização destas simulações depende de uma apresentação MEF desenvolvida adequadamente, de forma a tirar maior proveito deste realismo 3D. Neste trabalho, é realizado o desenvolvimento de um visualizador MEF 3D, que reproduz os efeitos estereoscópicos e de rastreamento de cabeça (head-tracking), explorando melhor as percepções de profundidade com hardware acessível e bibliotecas gráficas utilizadas em aplicações convencionais. / The 3D visualization of Finite Element Method (FEM) simulations is still a limited experience due to the lack of realism of 3D monitors available. In addition to the realistic 3D monitor, better visualization of these simulations depends on a MEF presentation properly developed in order to get the most out of 3D realism. In this work, a 3D MEF viewer is develop, including stereoscopy and head tracking 3D effects, that better explores human depth cues using hardware from cost and benefit perspective and graphics libraries used in conventional applications.
29

Caracterização e modelagem de redes biológicas geográficas / Characterization and modelling of biological networks

Viana, Matheus Palhares 23 March 2011 (has links)
Nesta tese apresentamos uma metodologia de mapeamento capaz de gerar representações em termos de grafos para sistemas biológicos de conectividade complexa. Tais sistemas são inicialmente armazenados na forma de imagens digitais e em seguida submetidos a um pré-processamento com objetivo de padronizar as imagens. As imagens pré-processadas são então utilizadas para gerar modelos tridimensionais dos sistemas de interesse. Um algoritmo de propagação de rótulos é utilizado para extrair os esqueletos dos modelos volumétricos e estes esqueletos são por fim, representados por um grafo, composto por vértices e arestas. Os vértices e arestas desse grafo armazenam propriedades do sistema original, como posição, comprimento e diâmetro, bem como as características topológicas de tais sistemas. Finalmente, os grafos resultantes são estudados através da teoria das redes complexas, dentro de um contexto específico para cada sistema. Nossos procedimentos foram aplicados com sucesso a diferentes sistemas biológicos, como artérias caríotidas, árvores arteriais, estruturas mitocondriais e poros em amostras de solo. / In the present work, we developed a mapping methodology able to build a graph representation for biological branched systems. Initially, such systems are stored as digital images and then they undergo a pre-processing in order to standardize the images. The pre-processed imagens are used to build tridimensional models of the interested systems. A label-propagation algorithm is used to extract the skeleton from the volumetric models and these skeletons are then represented by a graph, composed by nodes and edges. The nodes and edges of these graphs store properties of the original system, such as spatial position, lengths and diameter, as well as the topological features of such systems. Finally, the graphs are studied by using the complex networks theory within a specific context for each system. Our procedures were apllied sucefully to different biological systems, such as carotid artery, arterial trees, mitocondrial structure and pores in soil samples.
30

Fernerkundung und GIS zur Erfassung, Modellierung und Visualisierung orientalischer Stadtstrukturen : das Beispiel Sanaa (Jemen) / Acquisition, modelling and visualisation of oriental city structures with remote sensing and GIS : the case of Sanaa (Yemen)

Jamil, Abdlhamed January 2010 (has links)
Gegenstand dieser Arbeit ist die Konzeption, Entwicklung und exemplarische Implementierung eines generischen Verfahrens zur Erfassung, Verarbeitung, Auswertung und kartographischen Visualisierung urbaner Strukturen im altweltlichen Trockengürtel mittels hochauflösender operationeller Fernerkundungsdaten. Das Verfahren wird am Beispiel der jemenitischen Hauptstadt Sanaa einer Vertreterin des Typus der Orientalischen Stadt angewandt und evaluiert. Das zu entwickelnde Verfahren soll auf Standardverfahren und Systemen der raumbezogenen Informationsverarbeitung basieren und in seinen wesentlichen Prozessschritten automatisiert werden können. Daten von hochauflösenden operationellen Fernerkundungssystemen (wie z.B. QuickBird, Ikonos u. a.) erlauben die Erkennung und Kartierung urbaner Objekte, wie Gebäude, Straßen und sogar Autos. Die mit ihnen erstellten Karten und den daraus gewonnenen Informationen können zur Erfassung von Urbanisierungsprozessen (Stadt- und Bevölkerungswachstum) herangezogen werden. Sie werden auch zur Generierung von 3D-Stadtmodellen genutzt. Diese dienen z.B. der Visualisierung für touristische Anwendungen, für die Stadtplanung, für Lärmanalysen oder für die Standortplanung von Mobilfunkantennen. Bei dem in dieser Arbeit erzeugten 3D-Visualisierung wurden jedoch keine Gebäudedetails erfasst. Entscheidend war vielmehr die Wiedergabe der Siedlungsstruktur, die im Vorhandensein und in der Anordnung der Gebäude liegt. In dieser Arbeit wurden Daten des Satellitensensors Quickbird von 2005 verwendet. Sie zeigen einen Ausschnitt der Stadt Sanaa in Jemen. Die Fernerkundungsdaten wurden durch andere Daten, u.a. auch Geländedaten, ergänzt und verifiziert. Das ausgearbeitete Verfahren besteht aus der Klassifikation der Satellitenbild-aufnahme, die u.a. pixelbezogen und für jede Klasse einzeln (pixelbezogene Klassifikation auf Klassenebene) durchgeführt wurde. Zusätzlich fand eine visuelle Interpretation der Satellitenbildaufnahme statt, bei der einzelne Flächen und die Straßen digitalisiert und die Objekte mit Symbolen gekennzeichnet wurden. Die aus beiden Verfahren erstellten Stadtkarten wurden zu einer fusioniert. Durch die Kombination der Ergebnisse werden die Vorteile beider Karten in einer vereint und ihre jeweiligen Schwächen beseitigt bzw. minimiert. Die digitale Erfassung der Konturlinien auf der Orthophotomap von Sanaa erlaubte die Erstellung eines Digitalen Geländemodells, das der dreidimensionalen Darstellung des Altstadtbereichs von Sanaa diente. Die 3D-Visualisierung wurde sowohl von den pixelbezogenen Klassifikationsergebnissen auf Klassenebene als auch von der digitalen Erfassung der Objekte erstellt. Die Ergebnisse beider Visualisierungen wurden im Anschluss in einer Stadtkarte vereint. Bei allen Klassifikationsverfahren wurden die asphaltierten Straßen, die Vegetation und einzeln stehende Gebäude sehr gut erfasst. Die Klassifikation der Altstadt gestaltete sich aufgrund der dort für die Klassifikation herrschenden ungünstigen Bedingungen am problematischsten. Die insgesamt besten Ergebnisse mit den höchsten Genauigkeitswerten wurden bei der pixelbezogenen Klassifikation auf Klassenebene erzielt. Dadurch, dass jede Klasse einzeln klassifiziert wurde, konnte die zu einer Klasse gehörende Fläche besser erfasst und nachbearbeitet werden. Die Datenmenge wurde reduziert, die Bearbeitungszeit somit kürzer und die Speicherkapazität geringer. Die Auswertung bzw. visuelle Validierung der pixel-bezogenen Klassifikationsergebnisse auf Klassenebene mit dem Originalsatelliten-bild gestaltete sich einfacher und erfolgte genauer als bei den anderen durch-geführten Klassifikationsverfahren. Außerdem war es durch die alleinige Erfassung der Klasse Gebäude möglich, eine 3D-Visualisierung zu erzeugen. Bei einem Vergleich der erstellten Stadtkarten ergibt sich, dass die durch die visuelle Interpretation erstellte Karte mehr Informationen enthält. Die von den pixelbezogenen Klassifikationsergebnissen auf Klassenebene erstellte Karte ist aber weniger arbeits- und zeitaufwendig zu erzeugen. Zudem arbeitet sie die Struktur einer orientalischen Stadt mit den wesentlichen Merkmalen besser heraus. Durch die auf Basis der 2D-Stadtkarten erstellte 3D-Visualisierung wird ein anderer räumlicher Eindruck vermittelt und bestimmte Elemente einer orientalischen Stadt deutlich gemacht. Dazu zählen die sich in der Altstadt befindenden Sackgassen und die ehemalige Stadtmauer. Auch die für Sanaa typischen Hochhäuser werden in der 3D-Visualisierung erkannt. Insgesamt wurde in der Arbeit ein generisches Verfahren entwickelt, dass mit geringen Modifikationen auch auf andere städtische Räume des Typus orientalische Stadt angewendet werden kann. / This study aims at the development and implementation of a generic procedure for the acquisition, processing, analysis and cartographic visualisation of urban space in arid zone cities based on operational remote sensing imagery. As a proof of concept the Yemeni capital Sanaa has been selected as a use case. The workflow developed is based on standard procedures and systems of spatial information processing and allows for subsequent automation oft its essential processes. Today, high-resolution remote sensing data from operational satellite systems (such as QuickBird, Ikonos etc) facilitate the recognition and mapping of urban objects such as buildings, streets and even cars which, in the past could only be acquired by non-operational aerial photography. The satellite imagery can be used to generate maps and even 3D-representation of the urban space. Both maps and 3D-visualisations can be used for up-to-date land use mapping, zoning and urban planning purposes etc. The 3D-visualisation provides a deeper understanding of urban structures by integrating building height into the analysis. For this study remote sensing data of the Quickbird satellite data of 2005 were used. They show a section of the city of Sanaa in Yemen. The remote sensing data were supplemented and verified by other data, including terrain data. The image data are then subjected to thorough digital image. This procedure consists of a pixel-oriented classification of the satellite image acquisition at class level. In addition, a visual interpretation of the satellite image has been undertaken to identify and label individual objects (areas, surfaces, streets) etc. which were subsequently digitised. The town maps created in both procedures were merged to one. Through this combination of the results, the advantages of both maps are brought together and their respective weaknesses are eliminated or minimized. The digital collection of the contour lines on the orthophoto map of Sanaa allowed for the creation of a digital terrain model, which was used for the three-dimensional representation of Sanaa's historic district. The 3D-visualisation was created from the classification results as well as from the digital collection of the objects and the results of both visualisations were combined in a city map. In all classification procedures, paved roads, vegetation and single buildings were detected very well. The best overall results with the highest accuracy values achieved in the pixel-oriented classification at class level. Because each class has been classified separately, size belonging to that class can be better understood and optimised. The amount of data could be reduced, thus requiring less memory and resulting in a shorter processing time. The evaluation and validation of the pixel-oriented visual classification results at class level with the original satellite imagery was designed more simply and more accurately than other classification methods implemented. It was also possible by the separate recording of the class building to create a 3D-visualisation. A comparison of the maps created found that the map created from visual interpretation contains more information. The map based on pixel-oriented classification results at class level proved to be less labor- and time-consuming, and the structure of an oriental city with the main features will be worked out better. The 2D-maps and the 3D-visualisation provide a different spatial impression, and certain elements of an oriental city clearly detectable. These include the characteristic dead ends in the old town and the former city wall. The typical high-rise houses of Sanaa are detected in the 3D-visualisation. This work developed a generic procedure to detect, analyse and visualise urban structures in arid zone environments. The city of Sanaa served as a proof of concept. The results show that the workflow developed is instrumental in detecting typical structures of oriental cities. The results achieved in the case study Sanaa prove that the process can be adapted to the investigation of other arid zone cities in the Middle East with minor modifications.

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