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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.
11

Visualization using 3D Monitor / Visualisering vid använding av 3D Monitor

Hagdahl, Stefan January 2008 (has links)
Many companies over the years have been working with enhancing the visual effect of monitors and television with 3D glasses and such. There is a new form of 3D viewing right now; Spatial View is the one I know most about. Their technology includes a barrier panel technology which aligns the right and left eye simultaneously giving the person looking at the monitor a 3D viewing. Spatial View has developed an API that can be easily included in games and rendering applications to enable this 3D visualization and this thesis is about the computer performance cost. The API works in such a way that it takes 5 images of the current scene the camera is looking at in the game or rendering application and interlace them together to produce 1 image to be displayed on screen. Combining this with the monitor technique gives the visual effect. The 5 different camera angles that are produced can be a strain on the performance, meaning that the rendering API in this case Direct3D 9.0c has to render everything 5 times each frame. This can slow down the frame rate of the game, which is very important for the game to run smoothly. This thesis main focus is to understand the correlation between the number of camera angles and rendering time for Direct3D 9.0c, is it linear or exponential. By having access to Spatial View’s Direct3D 9.0c API, I was able to construct a test application which could answer the hypothesis. Six tests were used to investigate this with different numbers of camera angle to see the impact on rendering time. Using one, two and five camera angles for the test with large cubes (big enough to almost cover the screen) and small cubes (almost small enough to not see). After seeing the rendering time and understanding the API from Spatial View’s, a theory about reducing the rendering time arose. This theory will be explained throughout the thesis and discussed; it includes using Direct3D 10.0 with geometry instancing.
12

3D Teleconferencing : The construction of a fully functional, novel 3D Teleconferencing system / 3D Telekonferens : Konstruktionen av ett nytt, operativt 3D Teleconferanssystem

Lång, Magnus January 2009 (has links)
This report summarizes the work done to develop a 3D teleconferencing system, which enables remote participants anywhere in the world to be scanned in 3D, transmitted and displayed on a constructed 3D display with correct vertical and horizontal parallax, correct eye contact and eye gaze. The main focus of this report is the development of this system and especially how to in an efficient and general manner render to the novel 3D display. The 3D display is built out of modified commodity hardware and show a 3D scene for observers in up to 360 degrees around it and all heights. The result is a fully working 3D Teleconferencing system, resembling communication envisioned in movies such as holograms from Star Wars. The system transmits over the internet, at similar bandwidth requirements as concurrent 2D videoconferencing systems. / Project done at USC Institute for Creative Technologies, LA, USA. Presented at SIGGRAPH09.
13

Holoscopic 3D imaging and display technology : camera/processing/display

Swash, Mohammad Rafiq January 2013 (has links)
Holoscopic 3D imaging “Integral imaging” was first proposed by Lippmann in 1908. It has become an attractive technique for creating full colour 3D scene that exists in space. It promotes a single camera aperture for recording spatial information of a real scene and it uses a regularly spaced microlens arrays to simulate the principle of Fly’s eye technique, which creates physical duplicates of light field “true 3D-imaging technique”. While stereoscopic and multiview 3D imaging systems which simulate human eye technique are widely available in the commercial market, holoscopic 3D imaging technology is still in the research phase. The aim of this research is to investigate spatial resolution of holoscopic 3D imaging and display technology, which includes holoscopic 3D camera, processing and display. Smart microlens array architecture is proposed that doubles spatial resolution of holoscopic 3D camera horizontally by trading horizontal and vertical resolutions. In particular, it overcomes unbalanced pixel aspect ratio of unidirectional holoscopic 3D images. In addition, omnidirectional holoscopic 3D computer graphics rendering techniques are proposed that simplify the rendering complexity and facilitate holoscopic 3D content generation. Holoscopic 3D image stitching algorithm is proposed that widens overall viewing angle of holoscopic 3D camera aperture and pre-processing of holoscopic 3D image filters are proposed for spatial data alignment and 3D image data processing. In addition, Dynamic hyperlinker tool is developed that offers interactive holoscopic 3D video content search-ability and browse-ability. Novel pixel mapping techniques are proposed that improves spatial resolution and visual definition in space. For instance, 4D-DSPM enhances 3D pixels per inch from 44 3D-PPIs to 176 3D-PPIs horizontally and achieves spatial resolution of 1365 × 384 3D-Pixels whereas the traditional spatial resolution is 341 × 1536 3D-Pixels. In addition distributed pixel mapping is proposed that improves quality of holoscopic 3D scene in space by creating RGB-colour channel elemental images.
14

Scalable Volumetric Three-dimensional Up-conversion Display Medium

Cho, Jung-Hyun 01 January 2007 (has links)
There are many different techniques to display 3D information. However, not many of them are able to provide sufficient depth cues to the observers to sense or feel the images as real three-dimensional objects. Volumetric three-dimensional displays generate images within a real 3D space, so they provide most of the depth cues automatically. This thesis discusses the basic notions required to understand three-dimensional displays. Also discussed are different techniques used to display 3D information and their advantages and disadvantages as well as their current limitations. Several rare-earth doped fluoride crystals that are excited to emit visible light by sequential two photon absorption have been investigated as display medium candidates for static volumetric three dimensional displays. A scalable display medium is suggested to enable large 3D displays. This medium is a dispersion of particles of the rare earth doped fluoride crystals in a refractive index-matched polymer matrix. Detailed experiments are described to prepare such a scalable display medium using a wide variety of polymers. The scattering problem in such a medium was greatly reduced by index-matching the polymer to the crystalline particles. An index-matching condition that optimizes the performance was identified and demonstrated. A potential near-future solution is demonstrated and improvements are suggested.
15

Development of dual view displays

Mather, Jonathan Francis January 2007 (has links)
This thesis is about ‘Dual View’ displays. These are displays that can show different images to different people. For example, the driver of a car could view a GPS map, whilst the passenger who looks at the display from a different angle, could watch a movie. This thesis describes some of the research that took the project from an idea to a refined product. Sharp’s first dual view display is prototyped, and problems such as crosstalk between the two views are seen. These problems are analysed and rectified to bring the device up to a high standard. In July 2005 Sharp used this technology to launch the world’s first dual view product. Since then a new design of dual view display has been investigated. This design is theoretically optimised and experimentally tested. The new design is shown to provide dual view with greater head freedom, greater efficiency, and lower crosstalk than the original parallax barrier design.
16

Multi-Person Infrared Pupil Tracking for 3D TV without Glasses

Atan, Levent January 2012 (has links)
The success of recent 3-D stereoscopic movies such as Avatar has created a lot of attention for 3-D in the home. Almost all major consumer electronics (CE) manufacturers have launched their 3-D stereoscopic displays in the market. A problem with those solutions is that viewers have to wear glasses. Glasses-free autostereoscopic 3-D displays typically use lenticular lenses or barriers to create multiple views. However these displays suffer from a number of issues: inverted views at viewing cone transitions, cross-talk between views, and need for multi-view content.  As Philips Electronics research group, we believe that some of these issues can be reduced by using pupil tracking. In the research process, we began with an extensive literature study on people detection and tracking techniques that helped us to understand the benefits and the shortcomings of different applications. Addition to literature studies, we greatly benefited from constant experimentation with prototypes and the hands-on experience with variety of digital and optical components under different conditions. As a result, we designed a multi-person infrared pupil tracker and multi-view renderer for 3D display to adapt the view rendering in real-time according to viewer’s position. Together with the integration of these two applications, the integrated 3D TV successfully adapts the center view according to position of the viewer and able to provide a smooth transition while the viewer actively changes her position from a notable distance under ambient illumination. However, even though the pupil tracker is implemented for multiple people, because of the time limitation and the complexity of the problem regarding multi-view renderer, the integrated system functions only for one person.   Exploring the employed technique, in-depth description and detailed illustration of designed applications and the conclusions drawn from the implemented system; we believe that this paper forms a substantial guidance and show-how source for further research in the field of 3D display and people tracking methods.
17

Practical Structural Design and Control for Digital Clay

Zhu, Haihong 20 July 2005 (has links)
Digital Clay is a next generation human-machine communication interface based on a tangible haptic surface. This thesis embraces this revolutionary concept and seeks to give it a physical embodiment that will confirm its feasibility and enable experimentation relating to its utility and possible improvements. Per the approach adopted in work, Digital Clay could be described as a 3D monitor whose pixels can move perpendicularly to the screen to form a morphing surface. Users can view, touch and modify the shape of the working surface formed by these pixels. In reality, the pixels are the tips of micro hydraulic actuators or Hapcel (i.e. haptic cell, since the Digital Clay supports the haptic interface). The user can get a feel of the desired material properties when he/she touches the working surface. The potential applications of Digital Clay cover a wide range from computer aided engineering design to scientific research to medical diagnoses, 3D dynamic mapping and entertainment. One could predict a future in which, by using Digital Clay, not only could the user watch an actor in a movie, but also touch the face of the actor! This research starts from the review of the background of virtual reality. Then the concept and features of the proposed Digital Clay is provided. Research stages and a 5x5 cell array prototype are presented in this thesis on the structural design and control of Digital Clay. The first stage of the research focuses on the design and control of a single cell system of Digital Clay. Control issues of a single cell system constructed using conventional and off-the-shelf components are discussed first in detail followed by experimental results. Then practical designs of micro actuators and sensors are presented. The second stage of the research deals with the cell array system of Digital Clay. Practical structural design and control methods are discussed which are suitable for a 100x 100 (even 1000X 1000) cell array. Conceptual design and detailed implementations are presented. Finally, a 5 x 5 cell array prototype constructed using the discussed design solutions for testing is presented.
18

High-efficiency Blue Phase Liquid Crystal Displays

Li, Yan 01 January 2012 (has links)
Blue phase liquid crystals (BPLCs) have a delicate lattice structure existing between chiral nematic and isotropic phases, with a stable temperature range of about 2 K. But due to short coherent length, these self-assembled nano-structured BPLCs have a fast response time. In the past three decades, the application of BPLC has been rather limited because of its narrow temperature range. In 2002, Kikuchi et al. developed a polymer stabilization method to extend the blue-phase temperature range to more than 60 K. This opens a new gateway for display and photonic applications. In this dissertation, I investigate the material properties of polymer-stabilized BPLCs. According the Gerber’s model, the Kerr constant of a BPLC is linearly proportional to the dielectric anisotropy of the LC host. Therefore, in the frequency domain, the relaxation of the Kerr constant follows the same trend as the dielectric relaxation of the host LC. I have carried out experiments to validate the theoretical predictions, and proposed a model called extended Cole-Cole model to describe the relaxation of the Kerr constant. On the other hand, because of the linear relationship, the Kerr constant should have the same sign as the dielectric anisotropy of the LC host; that is, a positive or negative Kerr constant results from positive (∆ε > 0) or negative host LCs (∆ε < 0), respectively. BPLCs with a positive Kerr constant have been studied extensively, but there has been no study on negative ∆ε polymer-stabilized BPLCs. Therefore, I have prepared a BPLC mixture using a negative ∆ε LC host and investigated its electro-optic properties. I have demonstrated that indeed the induced birefringence and Kerr constant are of negative sign. Due to the fast response time of BPLCs, color sequential display is made possible without color breakup. By removing the spatial color filters, the optical efficiency and resolution density are both tripled. With other advantages such as alignment free and wide viewing angle, polymer-stabilized BPLC is emerging as a promising candidate for next-generation displays. However, the optical efficiency of the BPLC cell is relatively low and the operating voltage is quite high using conventional in-plane-switching electrodes. I have proposed several device structures for improving the optical efficiency of transmissive BPLC cells. Significant improvement in transmittance is achieved by using enhanced protrusion electrodes, and a 100% transmittance is achievable using complementary enhanced protrusion electrode structure. For a conventional transmissive blue phase LCD, although it has superb performances indoor, when exposed to strong sunlight the displayed images could be washed out, leading to a degraded contrast ratio and readability. To overcome the sunlight readability problem, a common approach is to adaptively boost the backlight intensity, but the tradeoff is in the increased power consumption. Here, I have proposed a transflective blue phase LCD where the backlight is turned on in dark surroundings while ambient light is used to illuminate the displayed images in bright surroundings. Therefore, a good contrast ratio is preserved even for a strong ambient. I have proposed two transflective blue phase LCD structures, both of which have single cell gap, single gamma driving, reasonably wide view angle, low power consumption, and high optical efficiency. Among all the 3D technologies, integral imaging is an attractive approach due to its high efficiency and real image depth. However, the optimum observation distance should be adjusted as the displayed image depth changes. This requires a fast focal length change of an adaptive lens array. BPLC adaptive lenses are a good candidate because of their intrinsic fast response time. I have proposed several BPLC lens structures which are polarization independent and exhibit a parabolic phase profile in addition to fast response time. To meet the low power consumption requirement set by Energy Star, high optical efficiency is among the top lists of next-generation LCDs. In this dissertation, I have demonstrated some new device structures for improving the optical efficiency of a polymerstabilized BPLC transmissive display and proposed sunlight readable transflective blue-phase LCDs by utilizing ambient light to reduce the power consumption. Moreover, we have proposed several blue-phase LC adaptive lenses for high efficiency 3D displays.
19

Optimal Stereo Reconstruction and 3D Visualization

Azari, Hossein Unknown Date
No description available.
20

Pokročilé metody snímání a hodnocení kvality 3D videa / Advanced Methods for 3D Video Capturing and Evaluation

Kaller, Ondřej January 2018 (has links)
Disertační práce se zabývá metodami snímání a hodnocení kvality 3D obrazů a videí. Po krátkém shrnutí fyziologie prostorového vnímání, obsahuje práce stav poznání v oblastech problému adaptivní paralaxy a konfigurace kamer pro snímání klasického stereopáru. Taktéž shrnuje dnešní možnosti odhadu hloubkové mapy. Zmíněny jsou aktivní i pasivní metody, detailněji je vysvětleno profilometrické skenování. Byly změřeny některé technické parametry dvou technologií současných 3D zobrazovačů, a to polarizačně-oddělujících a využívajících časový multiplex, například přeslechy mezi levým a pravým snímkem. Jádro práce tvoří nová metoda pro vytváření hloubkové mapy při snímání 3D scény, kterážto byla autorem navržena a testována. Inovativnost tohoto přístupu spočívá v chytré kombinaci současných aktivních a pasivních metod snímání hloubky scény, která vtipně využívá výhod obou metod. Nakonec jsou prezentovány výsledky subjektivních testů kvality 3D videa. Největší přínos zde má navržená metrika modelující výsledky subjektivních testů kvality 3D videa.

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