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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.
31

Putting it all together: Geophysical data integration

Kvamme, Kenneth L., Ernenwein, Eileen G., Menzer, Jeremy G. 01 January 2018 (has links)
The integration of information from multiple geophysical and other prospection surveys of archaeological sites and regions leads to a richer and more complete understanding of subsurface content, structure, and physical relationships. Such fusions of information occur within a single geophysical data set or between two or more geophysical and other prospection sources in one, two, or three dimensions. An absolute requirement is the accurate coregistration of all information to the same coordinate space. Data integrations occur at two levels. At the feature level, discrete objects that denote archaeological features are defined, usually subjectively, through the manual digitization of features interpreted in the data, although there is growing interest in automated feature identification and extraction. At the pixel level, distributional issues of skewness and outliers, high levels of noise that obfuscate targets of interest, and a lack of correlation between largely independent dimensions must be confronted. Nevertheless, successful fusions occur using computer graphic methods, simple arithmetic combinations, and advanced multivariate methods, including principal components analysis and supervised and unsupervised classifications. Four case studies are presented that illustrate some of these approaches and offer advancement into new domains.
32

Splat! Fragmented Space in Experimental Cinema

Szabados, Luke 13 May 2016 (has links)
No description available.
33

Utilizing the depth of the Landsat archive to reconstruct recent land change in the Carpathian ecoregion

Griffiths, Patrick 09 October 2013 (has links)
Fererkundliches monitoring von Landnutzungswandel ist eine Grundvoraussetzung um negative Auswirkungen globaler Umweltveränderungen zu reduzieren. Verfügbare Methoden unterliegen jedoch räumlichen und zeitlichen Einschränkungen. Die Öffnung des Landsat Archivs, bessere Datenqualität, fortgeschrittene Algorithmen und Rechenkapazitäten erlauben verbessertes Verständnis von Muster-Prozess Zusammenhängen, falls diese Einschränkungen überwunden werden. Das Ziel dieser Dissertation war es, Methoden zu entwickeln und anzuwenden, die eine bessere Nutzung des Landsat Archivs ermöglichen, um Landnutzungswandel in den Karpaten seit 1985 zu quantifizieren. Das sekundäre Ziel war es zu untersuchen, wie der Zusammenbruch des Sozialismus und der Beitritt zur Europäischen Union den regional Landnutzungswandel beeinträchtigt hat. Dafür wurde zunächst ein zeitreihenbasiertes Verfahren genutzt, um mittels verbesserter zeitlicher Auflösung ein besseres Verständnis von Waldstörungsdynamiken während der Umstrukturierung von Forstbesitzverhältnissen zu erlangen. Anschliessend wurden Compositing Algorithmen entwickelt, und mittels dieser die regionalen forst- und landwirtschaftlichen Veränderungen quantifiziert. Die Ergebnisse zeigten, dass das Ende des Sozialismus zu einer drastischen Reduzierung der Waldstörungen geführt hat und gleichzeitig weitflächig Ackerland aufgegeben wurde. Insgesamt nahm die Waldfläche leicht zu aber übermäßige Störungen erfolgten in verschiedenen Gebieten, verursacht durch den kombinierten Effekt forstwirtschaftlicher Vermächtnisse, natürlicher Störungen sowie Waldbewirtschaftung. Nach dem EU-Beitritt nahmen Störungsdynamiken in den Karpaten im Vergleich zu den ersten Übergangsjahren wieder zu, was auf neuorganiserte Forstwirtschaft mit Zugang zu EU Märkten hindeuten kann. Aufgegebene Ackerflächen wurden in den letzten Jahren vermehrt wiederbewirtschaftet, wahrscheinlich bedingt durch die Agrarpolitik der EU sowie einen zunehmenden Einfluss globaler Märkte. / Remote sensing based monitoring of land change is a prerequisite to reduce the negative impacts of global environmental change. However, available monitoring methods suffer from spatial and/or temporal limitations. The opening of the Landsat archive, advancements in data quality, processing algorithms and capabilities, can improve pattern-process understanding if these limitations are overcome. The overall aim of this dissertation was first, to develop and apply methods that better utilize the rich Landsat record and to map and quantify land change in the Carpathian ecoregion since 1985. The secondary objective is to investigate how the collapse of socialism and accession to the European Union (EU) affected regional land change. First, a trajectory based change detection approach was used to investigate how increased observation frequency helps understanding how forest ownership changes affected forest disturbance dynamics. Second, compositing algorithms are developed to facilitate mapping and change detection over large areas. This allowed assessing changes in forest cover and agriculture. Results showed that overall the collapse of socialism led to drastic declines in forest disturbances and simultaneously to widespread cropland abandonment. Forest cover overall expanded but excessive harvesting prevailed in certain areas, due to combined effects of land use legacies, natural disturbances and forest management. Following the EU accession, disturbance levels increased compared to the transition years, potentially relating to a re-established forestry sector with access to EU timber markets. Abandoned cropland was recultivated throughout the Carpathians during the most recent years, likely influenced by the EU Common Agricultural Policy and increasingly by global markets. This dissertation exemplifies the value of the Landsat archive for land change research which can improve our understanding of land change globally and thus help mitigate its negative impacts.
34

Video-Based 3D Textures

Mustafa, Mohammad January 2007 (has links)
<p>A new approach for object replacement in 3D space is presented. Introducing a technique that replaces the older two dimensional (2D) based facial replacement method performed by compositing artist in motion picture productions and video commercial industry.</p><p>This method uses 4 digital video cameras filming an actor from 360 degrees, the cameras are placed with 90 degrees in between, the video footage acquired is then used to produce a 3D video texture consisting of video segments taken from different angles representing the object from 3D point of view.</p><p>The video texture is then applied to a 3D modelled head matching the geometry of the original object.</p><p>Offering the freedom of showing the object from any point of view from 3D space, which is not possible using the current two dimensional method where the actormust at all time face the camera.</p><p>The method is described in details with images showing every stage of the process.</p><p>Results are presented as still frames taken from the final video footage and as a video file demonstrating them.</p>
35

Video-Based 3D Textures

Mustafa, Mohammad January 2007 (has links)
A new approach for object replacement in 3D space is presented. Introducing a technique that replaces the older two dimensional (2D) based facial replacement method performed by compositing artist in motion picture productions and video commercial industry. This method uses 4 digital video cameras filming an actor from 360 degrees, the cameras are placed with 90 degrees in between, the video footage acquired is then used to produce a 3D video texture consisting of video segments taken from different angles representing the object from 3D point of view. The video texture is then applied to a 3D modelled head matching the geometry of the original object. Offering the freedom of showing the object from any point of view from 3D space, which is not possible using the current two dimensional method where the actormust at all time face the camera. The method is described in details with images showing every stage of the process. Results are presented as still frames taken from the final video footage and as a video file demonstrating them.
36

Image Completion Using Local Images

Dalkvist, Mikael January 2011 (has links)
Image completion is a process of removing an area from a photograph and replacing it with suitable data. Earlier methods either search for this relevant data within the image itself, or extends the search to some form of additional data, usually some form of database. Methods that search for suitable data within the image itself has problems when no suitable data can be found in the image. Methods that extend their search has in earlier work either used some form of database with labeled images or a massive database with photos from the Internet. For the labels in a database to be useful they typically needs to be entered manually, which is a very time consuming process. Methods that uses databases with millions of images from the Internet has issues with copyrighted images, storage of the photographs and computation time. This work shows that a small database of the user’s own private, or professional, photos can be used to improve the quality of image completions. A photographer today typically take many similar photographs on similar scenes during a photo session. Therefore a smaller number of images are needed to find images that are visually and structurally similar, than when random images downloaded from the internet are used. Thus, this approach gains most of the advantages of using additional data for the image completions, while at the same time minimizing the disadvantages. It gains a better ability to find suitable data without having to process millions of irrelevant photos.
37

[en] VIDEO BASED INTERACTIVE STORYTELLING / [pt] STORYTELLING INTERATIVO BASEADO EM VÍDEO

EDIRLEI EVERSON SOARES DE LIMA 06 March 2015 (has links)
[pt] A geração de representações visuais envolventes para storytelling interativo é um dos desafios-chave para a evolução e popularização das narrativas interativas. Usualmente, sistemas de storytelling interativo utilizam computação gráfica para representar os mundos virtuais das histórias, o que facilita a geração dinâmica de conteúdos visuais. Embora animação tridimensional seja um poderoso meio para contar histórias, filmes com atores reais continuam atraindo mais atenção do público em geral. Além disso, apesar dos recentes progressos em renderização gráfica e da ampla aceitação de animação 3D em filmes, a qualidade visual do vídeo continua sendo muito superior aos gráficos gerados computacionalmente em tempo real. Na presente tese propomos uma nova abordagem para criar narrativas interativas mais envolventes, denominada Storytelling Interativo Baseado em Vídeo, onde os personagens e ambientes virtuais são substituídos por atores e cenários reais, sem perder a estrutura lógica da narrativa. Este trabalho apresenta um modelo geral para sistemas de storytelling interativo baseados em vídeo, incluindo os aspectos autorais das fases de produção e os aspectos técnicos dos algoritmos responsáveis pela geração em tempo real de narrativas interativas usando técnicas de composição de vídeo. / [en] The generation of engaging visual representations for interactive storytelling represents a key challenge for the evolution and popularization of interactive narratives. Usually, interactive storytelling systems adopt computer graphics to represent the virtual story worlds, which facilitates the dynamic generation of visual content. Although animation is a powerful storytelling medium, live-action films still attract more attention from the general public. In addition, despite the recent progress in graphics rendering and the wide-scale acceptance of 3D animation in films, the visual quality of video is still far superior to that of real-time generated computer graphics. In the present thesis, we propose a new approach to create more engaging interactive narratives, denominated Video-Based Interactive Storytelling, where characters and virtual environments are replaced by real actors and settings, without losing the logical structure of the narrative. This work presents a general model for interactive storytelling systems that are based on video, including the authorial aspects of the production phases, and the technical aspects of the algorithms responsible for the real-time generation of interactive narratives using video compositing techniques.
38

Matting of Natural Image Sequences using Bayesian Statistics

Karlsson, Fredrik January 2004 (has links)
<p>The problem of separating a non-rectangular foreground image from a background image is a classical problem in image processing and analysis, known as matting or keying. A common example is a film frame where an actor is extracted from the background to later be placed on a different background. Compositing of these objects against a new background is one of the most common operations in the creation of visual effects. When the original background is of non-constant color the matting becomes an under determined problem, for which a unique solution cannot be found. </p><p>This thesis describes a framework for computing mattes from images with backgrounds of non-constant color, using Bayesian statistics. Foreground and background color distributions are modeled as oriented Gaussians and optimal color and opacity values are determined using a maximum a posteriori approach. Together with information from optical flow algorithms, the framework produces mattes for image sequences without needing user input for each frame. </p><p>The approach used in this thesis differs from previous research in a few areas. The optimal order of processing is determined in a different way and sampling of color values is changed to work more efficiently on high-resolution images. Finally a gradient-guided local smoothness constraint can optionally be used to improve results for cases where the normal technique produces poor results.</p>
39

Matting of Natural Image Sequences using Bayesian Statistics

Karlsson, Fredrik January 2004 (has links)
The problem of separating a non-rectangular foreground image from a background image is a classical problem in image processing and analysis, known as matting or keying. A common example is a film frame where an actor is extracted from the background to later be placed on a different background. Compositing of these objects against a new background is one of the most common operations in the creation of visual effects. When the original background is of non-constant color the matting becomes an under determined problem, for which a unique solution cannot be found. This thesis describes a framework for computing mattes from images with backgrounds of non-constant color, using Bayesian statistics. Foreground and background color distributions are modeled as oriented Gaussians and optimal color and opacity values are determined using a maximum a posteriori approach. Together with information from optical flow algorithms, the framework produces mattes for image sequences without needing user input for each frame. The approach used in this thesis differs from previous research in a few areas. The optimal order of processing is determined in a different way and sampling of color values is changed to work more efficiently on high-resolution images. Finally a gradient-guided local smoothness constraint can optionally be used to improve results for cases where the normal technique produces poor results.
40

Renderingspass och linjärt arbetsflöde i färgrymd

Sahlin, Jimmy January 2012 (has links)
The film industry utilizes more and more computer generated visual effects and the visual effects industry and the surrounding community is continuously growing. It unlocks possibilities for the creative director that before was hard to achieve. And as technology advances, it does not only push the limit of the quality and complexity of the visual effects, but also allows ordinary people and amateurs with a tight budget to create stunning visuals as well.The report will cover render passes and the importance of a linear workflow. The report will determine common key material assets a compositor needs from rendering in order to have full control in post-production. Practical examples made with Maya and Nuke will be used. / <p>Validerat; 20120802 (anonymous)</p>

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