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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.
311

Multi-View Reconstruction and Camera Recovery using a Real or Virtual Reference Plane

Rother, Carsten January 2003 (has links)
<p>Reconstructing a 3-dimensional scene from a set of2-dimensional images is a fundamental problem in computervision. A system capable of performing this task can be used inmany applications in robotics, architecture, archaeology,biometrics, human computer interaction and the movie andentertainment industry.</p><p>Most existing reconstruction approaches exploit one sourceof information to tackle the problem. This is the motion of thecamera, the 2D images are taken from different viewpoints. Weexploit an additional information source, the reference plane,which makes it possible to reconstruct difficult scenes whereother methods fail. A real scene plane may serve as thereference plane. Furthermore, there are many alternativetechniques to obtain virtual reference planes. For instance,orthogonal directions in the scene provide a virtual referenceplane, the plane at infinity, or images taken with a parallelprojection camera. A collection of known and novel referenceplane scenarios is presented in this thesis.</p><p>The main contribution of the thesis is a novel multi-viewreconstruction approach using a reference plane. The techniqueis applicable to three different feature types, points, linesand planes. The novelty of our approach is that all cameras andall features (off the reference plane) are reconstructedsimultaneously from a single linear system of imagemeasurements. It is based on the novel observation that camerasand features have a linear relationship if a reference plane isknown. In the absence of a reference plane, this relationshipis non-linear. Thus many previousmethods must reconstructfeatures and cameras sequentially. Another class of methods,popular in the literature, is factorization, but, in contrastto our approach, this has the serious practical drawback thatall features are required to be visible in all views. Extensiveexperiments show that our approach is superior to allpreviously suggested reference plane and non-reference planemethods for difficult reference plane scenarios.</p><p>Furthermore, the thesis studies scenes which do not have aunique reconstruction, so-called critical configurations. It isproven that in the presence of a reference plane the set ofcritical configurations is small.</p><p>Finally, the thesis introduces a complete, automaticmulti-view reconstruction system based on the reference planeapproach. The input data is a set of images and the output a 3Dpoint reconstruction together with the correspondingcameras.</p>
312

Augmented Reality som ett hjälpmedel för produktvisualisering i möbelindustrin: en fallstudie

Johansson, Victor January 2009 (has links)
<p>This paper examines the potential benefits of using augmented reality as a tool for visualizing furniture in a buyer’s own environment before buying it. A simple prototype is developed and tested.  The steps for developing the prototype are described in great detail as well as the tools being used. The prototype is tested both on people working in the furniture business as well as people with experience in buying furniture online. In conclusion the results from the user tests are analyzed and the potential benefits are described. In addition to analyzing the potential benefits of the tool this paper also describes how this tool should be designed to best fit the needs of the would-be users.</p>
313

Development of computer vision algorithms using J2ME for mobile phone applications : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in the University of Canterbury /

Gu, Jian, January 1900 (has links)
Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). "November 2008." Includes bibliographical references (p. 91-96). Also available via the World Wide Web.
314

Visualisering av information vid navigering i skärgård : Utveckling av gränssnitt för informativa 3D-kartor/sjökort / Information visualization for navigation in archipelago areas

Olofsson, Anna January 2015 (has links)
Denna rapport beskriver process och resultat av ett examensarbete inom produktutveckling, genomfört vid Linköpings universitet under vårterminen 2015. Examensarbetet har skett i samarbete med Reality Labs vid Combitech AB och varit en del av ett projekt som syftar till att utveckla ett informativt navigeringshjälpmedel för båtturister på Kosteröarna. Fokus i examensarbetet har varit användbarhet och visualisering, och målet har varit att utveckla ett koncept för produktens gränssnitt. Detta genomfördes i fyra steg; användarstudie, konceptutveckling, prototyputveckling och prototyputvärdering. I användarstudien intervjuades 10 personer, fem med erfarenhet av navigering med båt och fem utan sådan erfarenhet, om vilka krav och önskemål som finns på ett hjälpmedel för att dels navigera och dels få en positiv helhetsupplevelse av Kosteröarna. Konceptutvecklingen skedde i ett antal steg där antalet alternativa koncept minskades för varje steg samtidigt som detaljgraden ökades för de kvarvarande alternativen, tills ett slutligt koncept tagits fram. Detta koncept innefattade tre olika lägen; planera, navigera och upptäcka, för att kunna ge användaren en personlig upplevelse. Genom ett omfattande planeringsverktyg möjliggörs att användaren får förslag baserat på personliga preferenser. Dessutom läggs största delen av användarens beslutsfattande i planeringsstadiet, vilket begränsar mängden information som ges under navigering. Två prototyper togs fram; en pappersprototyp innefattande alla tre lägen samt en interaktiv prototyp innefattande enbart läget navigera. Dessa prototyper utvärderades tillsammans med några av de användare som deltagit i användarstudien. Konceptet som helhet fick mycket positiv feedback, men också konstruktiva synpunkter som kan tas vidare för förbättring av konceptet. Även om det inte finns utrymme för vidare arbete inom examensarbetet kan användarnas synpunkter bidra med värdefulla insikter till projektet. / This report describes the process and result of a master thesis in product development, conducted at Linköping university during spring term 2015. The master thesis has been carried out in cooperation with Reality Labs at Combitech AB and has been a part of a project aiming to develop an informative navigation equipment for boat tourists at Koster islands. The focus of the thesis has been usability and visualization, and the objective has been to develop a concept for the interface of the product. This was conducted through four steps; user study, concept development, prototype development and prototype evaluation. For the user study, 10 participants were interviewed, five with experience from navigation with a boat and five without such experience. The interviews were about what requirements and requests there are for an equipment made for both navigation and providing a positive overall experience of the Koster islands. The concept development was conducted through several steps, i which the number of alternative concepts decreased for each step while the level of detail was increased for the remaining alternatives, until one final concept had been developed. The concept included three different modes; plan, navigate and explore, in order to provide the user with a personal experience. Using an extensive planning tool, it is possible for the user to receive suggestions based on personal preferences. Furthermore, the most of the user’s decisions are made during the planning stage, limiting the amount of information provided during navigation. Two prototypes were developed; one paper prototype including all the three modes and one interactive prototype incuding only the navigate mode. These prototypes were evaluated with some of the participants from the user study. The concept received a large amount of positive feedback, but also constructive comments that can be used for furthur improvement of the concept. Even though there is no room for furthur development within this master thesis, the users’ opinions can provide valuable insights for the project.
315

Fusion of carrier-phase differential GPS, bundle-adjustment-based visual SLAM, and inertial navigation for precisely and globally-registered augmented reality

Shepard, Daniel Phillip 16 September 2013 (has links)
Methodologies are proposed for combining carrier-phase differential GPS (CDGPS), visual simultaneous localization and mapping (SLAM), and inertial measurements to obtain precise and globally-referenced position and attitude estimates of a rigid structure connecting a GPS receiver, a camera, and an inertial measurement unit (IMU). As part of developing these methodologies, observability of globally-referenced attitude based solely on GPS-based position estimates and visual feature measurements is proven. Determination of attitude in this manner eliminates the need for attitude estimates based on magnetometer and accelerometer measurements, which are notoriously susceptible to magnetic disturbances. This combination of navigation techniques, if coupled properly, is capable of attaining centimeter-level or better absolute positioning and degree-level or better absolute attitude accuracies in any space, both indoors and out. Such a navigation system is ideally suited for application to augmented reality (AR), which often employs a GPS receiver, a camera, and an IMU, and would result in tight registration of virtual elements to the real world. A prototype AR system is presented that represents a first step towards coupling CDGPS, visual SLAM, and inertial navigation. While this prototype AR system does not couple CDGPS and visual SLAM tightly enough to obtain some of the benefit of the proposed methodologies, the system is capable of demonstrating an upper bound on the precision that such a combination of navigation techniques could attain. Test results for the prototype AR system are presented for a dynamic scenario that demonstrate sub-centimeter-level positioning precision and sub-degree-level attitude precision. This level of precision would enable convincing augmented visuals. / text
316

Bringing Augmented Reality to Mobile Phones

Henrysson, Anders January 2007 (has links)
With its mixing of real and virtual, Augmented Reality (AR) is a technology that has attracted lots of attention from the science community and is seen as a perfect way to visualize context-related information. Computer generated graphics is presented to the user overlaid and registered with the real world and hence augmenting it. Promising intelligence amplification and higher productivity, AR has been intensively researched over several decades but has yet to reach a broad audience. This thesis presents efforts in bringing Augmented Reality to mobile phones and thus to the general public. Implementing technologies on limited devices, such as mobile phones, poses a number of challenges that differ from traditional research directions. These include: limited computational resources with little or no possibility to upgrade or add hardware, limited input and output capabilities for interactive 3D graphics. The research presented in this thesis addresses these challenges and makes contributions in the following areas: Mobile Phone Computer Vision-Based Tracking The first contribution of thesis has been to migrate computer vision algorithms for tracking the mobile phone camera in a real world reference frame - a key enabling technology for AR. To tackle performance issues, low-level optimized code, using fixed-point algorithms, has been developed. Mobile Phone 3D Interaction Techniques Another contribution of this thesis has been to research interaction techniques for manipulating virtual content. This is in part realized by exploiting camera tracking for position-controlled interaction where motion of the device is used as input. Gesture input, made possible by a separate front camera, is another approach that is investigated. The obtained results are not unique to AR and could also be applicable to general mobile 3D graphics. Novel Single User AR Applications With short range communication technologies, mobile phones can exchange data not only with other phones but also with an intelligent environment. Data can be obtained for tracking or visualization; displays can be used to render graphics with the tracked mobile phone acting as an interaction device. Work is presented where a mobile phone harvests a sensor-network to use AR to visualize live data in context. Novel Collaboration AR Applications One of the most promising areas for mobile phone based AR is enhancing face-to-face computer supported cooperative work. This is because the AR display permits non-verbal cues to be used to a larger extent. In this thesis, face-to-face collaboration has been researched to examine whether AR increases awareness of collaboration partners even on small devices such as mobile phones. User feedback indicates that this is the case, confirming the hypothesis that mobile phones are increasingly able to deliver an AR experience to a large audience. / On the day of the defence date the status on articles III and VIII was: Accepted.
317

Stereoscopic Label Placement : Reducing Distraction and Ambiguity in Visually Cluttered Displays

Peterson, Stephen D. January 2009 (has links)
With increasing information density and complexity, computer displays may become visually cluttered, adversely affecting overall usability. Text labels can significantly add to visual clutter in graphical user interfaces, but are generally kept legible through specific label placement algorithms that seek visual separation of labels and other objects in the 2D view plane. This work studies an alternative approach: can overlapping labels be visually segregated by distributing them in stereoscopic depth? The fact that we have two forward-looking eyes yields stereoscopic disparity: each eye has a slightly different perspective on objects in the visual field. Disparity is used for depth perception by the human visual system, and is therefore also provided by stereoscopic 3D displays to produce a sense of depth. This work has shown that a stereoscopic label placement algorithm yields user performance comparable with existing algorithms that separate labels in the view plane. At the same time, such stereoscopic label placement is subjectively rated significantly less disturbing than traditional methods. Furthermore, it does not allow for potentially ambiguous spatial relationships between labels and background objects inherent to labels separated in the view plane. These findings are important for display systems where disturbance, distraction and ambiguity of the overlay can negatively impact safety and efficiency of the system, including the reference application of this work: an augmented vision system for Air Traffic Control towers.
318

Illusion SDK: An Augmented Reality Engine for Flash 11

Howse, Joseph 20 November 2012 (has links)
This thesis presents Illusion SDK: a general, extensible framework for augmented reality (AR) applications. Illusion provides loosely coupled or decoupled abstractions of sensors, trackers, and compositors. Implementations are optimized for particular use cases. Illusion’s architecture depends on only an event system and a 3D scene graph, so it is highly portable. Wrapping of third-party trackers is supported. Illusion’s current implementation targets Flash 11.4 and integrates with the Alternativa3D 8 graphics engine. To our knowledge, Illusion’s support for wrapping third-party trackers is unique among toolkits targeting the GPU-accelerated Web. Illusion performs well on MacBook Pro 13" mid-2010, where an intensive camera application can exceed 45 FPS. Generally, Illusion should perform well on hardware that uses shared video memory. Optimizations are needed for hardware that uses dedicated video memory. These optimizations are problematic in Flash 11.4 but should not generally be problematic in ports to other platforms.
319

Nonogram solving algorithms analysis and implementation for augmented reality system / Japoniškų kryžiažodžių sprendimo algoritmų suprogramavimas ir tyrimas

Zavistanavičius, Ramūnas 04 November 2013 (has links)
Augmented reality (AR) is an innovative use of computer graphics in combination with real world data to create a new kind of video image. AR seamlessly integrates technology with the real world, allowing for a naturally enhanced computing. Nonograms, also known as Paint by Numbers or Griddlers are logic puzzles in which cells in a grid have to be colored or left blank according to numbers given at the side of the grid to reveal a hidden picture. In this puzzle type, the numbers measure how many unbroken lines of filled-in squares there are in any given row or column. Aim of this project is to implement and compare nonogram solution algorithms and find out which algorithm is suitable for mobile device running Android operating system. / Papildyta realybė yra inovatyvus kompiuterinės grafikos ir realaus pasaulio vaizdų panaudojimas, sukuriantis naują vaizdą. Papildyta realybė sklandžiai integruoja technologijas realiame pasaulyje, leisdama natūraliai naudotis naujausiomis technologijomis. Nonogramos, dar žinomos kaip Japoniški gryžiažodžiai, yra loginis galvosūkis. Norint išspręsti šį galvosūkį lentelės langeliai turi būti nuspalvinti arba palikti tušti priklausomai nuo skaičių, esančių lentelės šone ir viršuje, taip atskleidžiant paslėptą paveikslėlį. Šio tipo galvosūkiuose skaičiai parodo kiek vientisų užspalvintų langelių yra duotoje eilutėje arba stulpelyje. Šio darbo tikslas yra suprogramuoti ir palyginti nonogramų sprendimo algoritmus ir nustatyti, kuris iš jų yra tinkamesnis naudoti išmaniuosiuose telefonuose su Android operacine sistema.
320

The fAARS Platform, For Augmented Alternate Reality Services and Games

Gutierrez, Lucio, Al Unknown Date
No description available.

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