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dc.identifier.urihttp://hdl.handle.net/1951/59816
dc.identifier.urihttp://hdl.handle.net/11401/71369
dc.description.sponsorshipThis work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.en_US
dc.formatMonograph
dc.format.mediumElectronic Resourceen_US
dc.language.isoen_US
dc.publisherThe Graduate School, Stony Brook University: Stony Brook, NY.
dc.typeDissertation
dcterms.abstractImage formation is a function of three components: scene geometry, surface reflectance and illumination. Estimation of one or more of these components from an image gives rise to inverse rendering problems, such as shape reconstruction or illumination estimation, which are the two major problems of interest in this thesis. We formulate such problems in a way that attempts to bridge the gap between low-level approaches based on the physical laws governing image formation and higher-level models that examine images in a statistical way. We take advantage of the powerful formalism offered by graphical models, which lead to modular frameworks and offer powerful discrete optimization techniques. We first focus on the problem of illumination estimation from a single image, utilizing the information in cast shadows. We start by describing a method to extract cast shadows from an image. We then present three approaches to illumination estimation from shadows: The first models illumination as a mixture of distributions to robustly estimate illumination. The second associates illumination not with pixel intensities but with the existence of shadow edges. The third approach unifies the previous ideas in a Markov Random Field (MRF) framework. Such a model is robust to coarse or incomplete knowledge of geometry, while it can also incorporate geometric parameters, allowing us to jointly infer three major components of the problem: the cast shadows, illumination and geometry. Geometry inference from the information contained in cast shadows can only be coarse, however. We subsequently focus on the problem of inferring geometry from the shading variations in an image. We take a data-driven approach, constructing a dictionary of geometric primitives. To reconstruct an image, we combine local hypotheses from this dictionary in an MRF model. We demonstrate that this approach can effectively reconstruct 3D shapes from real photographs, while removing several important assumptions of previous approaches.
dcterms.available2013-05-22T17:35:22Z
dcterms.available2015-04-24T14:47:13Z
dcterms.contributorBerg, Tamaraen_US
dcterms.contributorSamaras, Dimitrisen_US
dcterms.contributorBerg, Alexanderen_US
dcterms.contributorForsyth, David.en_US
dcterms.creatorPanagopoulos, Alexandros
dcterms.dateAccepted2013-05-22T17:35:22Z
dcterms.dateAccepted2015-04-24T14:47:13Z
dcterms.dateSubmitted2013-05-22T17:35:22Z
dcterms.dateSubmitted2015-04-24T14:47:13Z
dcterms.descriptionDepartment of Computer Scienceen_US
dcterms.extent155 pg.en_US
dcterms.formatMonograph
dcterms.formatApplication/PDFen_US
dcterms.identifierhttp://hdl.handle.net/1951/59816
dcterms.identifierPanagopoulos_grad.sunysb_0771E_10809en_US
dcterms.identifierhttp://hdl.handle.net/11401/71369
dcterms.issued2011-12-01
dcterms.languageen_US
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dcterms.provenanceMade available in DSpace on 2015-04-24T14:47:13Z (GMT). No. of bitstreams: 3 Panagopoulos_grad.sunysb_0771E_10809.pdf.jpg: 1894 bytes, checksum: a6009c46e6ec8251b348085684cba80d (MD5) Panagopoulos_grad.sunysb_0771E_10809.pdf.txt: 284243 bytes, checksum: 693a56a86fe9161fb24fcd904f111788 (MD5) Panagopoulos_grad.sunysb_0771E_10809.pdf: 22784942 bytes, checksum: 34f5baec6856006b220b4558a178b949 (MD5) Previous issue date: 1en
dcterms.publisherThe Graduate School, Stony Brook University: Stony Brook, NY.
dcterms.subjectComputer science
dcterms.subjectcomputer vision, illumination estimation, shape-from-shading
dcterms.titleIllumination and Geometry Inference Using Graphical Models
dcterms.typeDissertation


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