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dc.contributor.authorCatchpole, Jason Jamesen_NZ
dc.date.accessioned2008-11-17T08:42:39Z
dc.date.available2008-11-21T13:16:45Z
dc.date.issued2008en_NZ
dc.identifier.citationCatchpole, J. J. (2008). Adaptive Vision Based Scene Registration for Outdoor Augmented Reality (Thesis, Doctor of Philosophy (PhD)). The University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/2581en
dc.identifier.urihttps://hdl.handle.net/10289/2581
dc.description.abstractAugmented Reality (AR) involves adding virtual content into real scenes. Scenes are viewed using a Head-Mounted Display or other display type. In order to place content into the user's view of a scene, the user's position and orientation relative to the scene, commonly referred to as their pose, must be determined accurately. This allows the objects to be placed in the correct positions and to remain there when the user moves or the scene changes. It is achieved by tracking the user in relation to their environment using a variety of technology. One technology which has proven to provide accurate results is computer vision. Computer vision involves a computer analysing images and achieving an understanding of them. This may be locating objects such as faces in the images, or in the case of AR, determining the pose of the user. One of the ultimate goals of AR systems is to be capable of operating under any condition. For example, a computer vision system must be robust under a range of different scene types, and under unpredictable environmental conditions due to variable illumination and weather. The majority of existing literature tests algorithms under the assumption of ideal or 'normal' imaging conditions. To ensure robustness under as many circumstances as possible it is also important to evaluate the systems under adverse conditions. This thesis seeks to analyse the effects that variable illumination has on computer vision algorithms. To enable this analysis, test data is required to isolate weather and illumination effects, without other factors such as changes in viewpoint that would bias the results. A new dataset is presented which also allows controlled viewpoint differences in the presence of weather and illumination changes. This is achieved by capturing video from a camera undergoing a repeatable motion sequence. Ground truth data is stored per frame allowing images from the same position under differing environmental conditions, to be easily extracted from the videos. An in depth analysis of six detection algorithms and five matching techniques demonstrates the impact that non-uniform illumination changes can have on vision algorithms. Specifically, shadows can degrade performance and reduce confidence in the system, decrease reliability, or even completely prevent successful operation. An investigation into approaches to improve performance yields techniques that can help reduce the impact of shadows. A novel algorithm is presented that merges reference data captured at different times, resulting in reference data with minimal shadow effects. This can significantly improve performance and reliability when operating on images containing shadow effects. These advances improve the robustness of computer vision systems and extend the range of conditions in which they can operate. This can increase the usefulness of the algorithms and the AR systems that employ them.en_NZ
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.publisherThe University of Waikatoen_NZ
dc.rightsAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectcomputer visionen_NZ
dc.subjectaugmented realityen_NZ
dc.subjectARen_NZ
dc.subjectnon-uniform illuminationen_NZ
dc.subjectshadowsen_NZ
dc.subjectlocal feature detectoren_NZ
dc.subjectMSERen_NZ
dc.subjectSIFTen_NZ
dc.subjectaffine covarianten_NZ
dc.titleAdaptive Vision Based Scene Registration for Outdoor Augmented Realityen_NZ
dc.typeThesisen_NZ
thesis.degree.disciplineSchool of Computing and Mathematical Scienceen_NZ
thesis.degree.grantorUniversity of Waikatoen_NZ
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy (PhD)en_NZ
uow.date.accession2008-11-17T08:42:39Zen_NZ
uow.date.available2008-11-21T13:16:45Zen_NZ
uow.identifier.adthttp://adt.waikato.ac.nz/public/adt-uow20081117.084239en_NZ
uow.date.migrated2009-06-12T04:52:05Zen_NZ
pubs.place-of-publicationHamilton, New Zealanden_NZ


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