Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites

 

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dc.contributor.advisor Blake, Edwin H en_ZA
dc.contributor.author Williams, John G en_ZA
dc.date.accessioned 2014-10-25T18:59:21Z
dc.date.available 2014-10-25T18:59:21Z
dc.date.issued 2001 en_ZA
dc.identifier.citation Williams, J. 2001. Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/8776
dc.description Bibliography: leaves 100-104. en_ZA
dc.description.abstract A tool has been designed and implemented to use information extracted from photographs captured using uncalibrated cameras (so-called casual photographs) to fill the occlusions which occur in three-dimensional models of photogrammetrically captured sites. Capturing the geometry of archaeological sites by photogrammetric means is relatively expensive and, because of the layouts typical of such sites, usually results in a degree of occlusion. Occlusions are filled by extracting texture and calculating hidden geometry from casual photographs with the support of three-dimensional geometric data gleaned from the photogrammetric survey. The essential philosophy underlying the tool is to segment each occlusion into surfaces which may be approximated using curves and then use known geometry in the region of the occlusion to calculate the most probable locations of the junctions of such surface segments. The tool is primarily a combination of existing techniques for pre-filtering and calibrating the casual photograph, boundary detection and ultimately texture adjustment. The technique implemented for calculating the locations of occluded comers using minimisation of least square errors is new. The tool has been applied to occlusions of the various configurations that are expected to be typical of archaeological sites and has been found to deal well with such features and to provide accurate patches from typical data sets. It is also shown that the three-dimensional geometric model is clearly improved by the filling-in of the occlusion. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Computer Science en_ZA
dc.title Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites en_ZA
dc.type Master Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Computer Science en_ZA
dc.type.qualificationlevel Masters
dc.type.qualificationname MSc en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Williams, J. G. (2001). <i>Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Computer Science. Retrieved from http://hdl.handle.net/11427/8776 en_ZA
dc.identifier.chicagocitation Williams, John G. <i>"Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Computer Science, 2001. http://hdl.handle.net/11427/8776 en_ZA
dc.identifier.vancouvercitation Williams JG. Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Computer Science, 2001 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/8776 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Williams, John G AB - A tool has been designed and implemented to use information extracted from photographs captured using uncalibrated cameras (so-called casual photographs) to fill the occlusions which occur in three-dimensional models of photogrammetrically captured sites. Capturing the geometry of archaeological sites by photogrammetric means is relatively expensive and, because of the layouts typical of such sites, usually results in a degree of occlusion. Occlusions are filled by extracting texture and calculating hidden geometry from casual photographs with the support of three-dimensional geometric data gleaned from the photogrammetric survey. The essential philosophy underlying the tool is to segment each occlusion into surfaces which may be approximated using curves and then use known geometry in the region of the occlusion to calculate the most probable locations of the junctions of such surface segments. The tool is primarily a combination of existing techniques for pre-filtering and calibrating the casual photograph, boundary detection and ultimately texture adjustment. The technique implemented for calculating the locations of occluded comers using minimisation of least square errors is new. The tool has been applied to occlusions of the various configurations that are expected to be typical of archaeological sites and has been found to deal well with such features and to provide accurate patches from typical data sets. It is also shown that the three-dimensional geometric model is clearly improved by the filling-in of the occlusion. DA - 2001 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2001 T1 - Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites TI - Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites UR - http://hdl.handle.net/11427/8776 ER - en_ZA


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