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Reference: Glennerster, Andrew., (1993). The role of spatial scale in binocular stereopsis. DPhil. University of Oxford.Citable link to this page:


The role of spatial scale in binocular stereopsis

Abstract: A model of stereopsis is proposed in which information from each eye's image isorganised as a scale-based hierarchy before binocular comparison. The algorithmincorporates coarse-to-fine matching (like Marr and Poggio, 1979) but differs fromprevious models in that the position, and hence disparity, of features is definedrelatively rather than by their retinal co-ordinate. Thus, fine scale disparities aremeasured and recorded relative to coarse scale disparities. Local surface slant andcurvature is represented explicitly at a range of spatial scales. The theory is basedon a hierarchical model of encoding position (Watt, 1988).The first experiment investigates the time course of shape discrimination in randomdot stereograms. The results are compatible with a model in which the scale ofanalysis changes from coarse to fine over the first second of viewing. The secondexperiment measures the magnitude of a new 3-D Müller-Lyer illusion andcompares it to that of the classical (2-D) illusion. Both these and the cyclopeanMüller-Lyer illusion are consistent with a model in which hierarchical encoding ofposition is used by the visual system for 2-D (length comparison) and 3-D (slant)judgements. The third experiment compares the detection of large disparities andlarge displacements. Dmax for the motion and stereo tasks is shown to be similarover a wide range of dot densities. The results are interpreted as evidence thatsimilar spatial primitives are used in the correspondence process in both domains.The spacing of MIRAGE centroids (Watt and Morgan, 1985) fit the data well.The proposed hierarchical model is similar to that put forward by Mitchison andMcKee (1987), although their scheme was not based on spatial scale. The modelbridges the gap between a primal and a 2 1/2-D sketch (Marr, 1982) and hasimportant implications for many issues within stereopsis.

Type of Award:DPhil Level of Award:Doctoral Awarding Institution: University of Oxford Notes:This thesis was digitised thanks to the generosity of Dr Leonard Polonsky


Rogers, Brian J.More by this contributor



Dr. Brian RogersMore by this contributor


 Bibliographic Details

Issue Date: 1993Identifiers

Urn: uuid:13ecf058-eea2-4c4c-8d25-332a8827b774

Source identifier: 603851308 Item Description

Type: Thesis;

Language: eng Subjects: Binocular vision Visual perception Tiny URL: td:603851308


Author: Glennerster, Andrew. - institutionUniversity of Oxford facultyMedical Sciences Division - - - - Contributors Rogers, Brian J. Mor



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