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Qualitative Depth From Stereo, With Applications
 Computer Vision, Graphics, and Image Processing
, 1990
"... Obtaining exact depth from binocular disparities is hard if camera calibration is needed. We will show that qualitative information can be obtained from stereo disparities with little computation, and without prior knowledge (or computation) of camera parameters. First, we derive two expressions tha ..."
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Cited by 16 (2 self)
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Obtaining exact depth from binocular disparities is hard if camera calibration is needed. We will show that qualitative information can be obtained from stereo disparities with little computation, and without prior knowledge (or computation) of camera parameters. First, we derive two expressions that order all matched points in the images by depth in two distinct ways from image coordinates only. Using one for tilt estimation and point separation (in depth) demonstrates some anomalies observed in psychophysical experiments, most notably the "induced size effect". We apply the same approach to detect qualitative changes in the curvature of a contour on the surface of an object, with either x or ycoordinate fixed. Second, we develop an algorithm to compute axes of zerocurvature from disparities alone. The algorithm is shown to be quite robust against violations of its basic assumptions for synthetic data with relatively large controlled deviations. It performs almost as well on real i...
Multiresolution Estimation of 2d Disparity Using a Frequency Domain Approach
, 1992
"... An efficient algorithm for the estimation of the 2d disparity between a pair of stereo images is presented. Phase based methods are extended to the case of 2d disparities and shown to correspond to computing local correlation fields. These are derived at multiple scales via the frequency domain an ..."
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Cited by 16 (9 self)
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An efficient algorithm for the estimation of the 2d disparity between a pair of stereo images is presented. Phase based methods are extended to the case of 2d disparities and shown to correspond to computing local correlation fields. These are derived at multiple scales via the frequency domain and a coarsetofine `focusing' strategy determines the final disparity estimate. Fast implementation is achieved by using a generalised form of wavelet transform, the multiresolution Fourier transform (MFT), which enables efficient calculation of the local correlations. Results from initial experiments on random noise stereo pairs containing both 1d and 2d disparities, illustrate the potential of the approach. 1 Introduction Estimating the disparity between a pair of binocular images in order to determine depth information from a scene has received considerable attention for many years. Essentially a problem of finding corresponding points in the two views of the scene, the complexity of t...
Cyclopean geometry of binocular vision
"... The geometry of binocular projection is analyzed in relation to the primate visual system. An oculomotor parameterization that includes the classical vergence and version angles is defined. It is shown that the epipolar geometry of the system is constrained by binocular coordination of the eyes. A l ..."
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Cited by 14 (9 self)
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The geometry of binocular projection is analyzed in relation to the primate visual system. An oculomotor parameterization that includes the classical vergence and version angles is defined. It is shown that the epipolar geometry of the system is constrained by binocular coordination of the eyes. A local model of the scene is adopted in which depth is measured relative to a plane containing the fixation point. These constructions lead to an explicit parameterization of the binocular disparity field involving the gaze angles as well as the scene structure. The representation of visual direction and depth is discussed with reference to the relevant psychophysical and neurophysiological literature. © 2008 Optical Society of America OCIS codes: 330.1400, 330.2210. 1.
Author manuscript, published in "Joural of the Optical Society of America A (2008)" Cyclopean Geometry of Binocular Vision
, 2009
"... The geometry of binocular projection is analyzed in relation to the primate visual system. An oculomotor parameterization, which includes the classical vergence and version angles, is defined. It is shown that the epipolar geometry of the system is constrained by binocular coordination of the eyes. ..."
Abstract
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The geometry of binocular projection is analyzed in relation to the primate visual system. An oculomotor parameterization, which includes the classical vergence and version angles, is defined. It is shown that the epipolar geometry of the system is constrained by binocular coordination of the eyes. A local model of the scene is adopted, in which depth is measured relative to a plane containing the fixation point. These constructions lead to an explicit parameterization of the binocular disparity field, involving the gaze angles as well as the scene structure. The representation of visual direction and depth is discussed, with reference to the relevant psychophysical and neurophysiological literature. 1
PART I DEPTH PROCESSING AND STEREOPSIS
"... Physiologically based models of binocular depth perception ning qian and yongjie li We perceive the world as threedimensional. The inputs to our visual system, however, are only a pair of twodimensional projections on the two retinal surfaces. As emphasized by Marr and Poggio (1976), it is general ..."
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Physiologically based models of binocular depth perception ning qian and yongjie li We perceive the world as threedimensional. The inputs to our visual system, however, are only a pair of twodimensional projections on the two retinal surfaces. As emphasized by Marr and Poggio (1976), it is generally impossible to uniquely determine the threedimensional world from its twodimensional
Horizontal and vertical disparity, eye position, and stereoscopic slant perception
, 1998
"... The slant of a stereoscopically defined surface cannot be determined solely from horizontal disparities or from derived quantities such as horizontal size ratio (HSR). There are four other signals that, in combination with horizontal disparity, could in principle allow an unambiguous estimate of sla ..."
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The slant of a stereoscopically defined surface cannot be determined solely from horizontal disparities or from derived quantities such as horizontal size ratio (HSR). There are four other signals that, in combination with horizontal disparity, could in principle allow an unambiguous estimate of slant: the vergence and version of the eyes, the vertical size ratio (VSR), and the horizontal gradient of VSR. Another useful signal is provided by perspective slant cues. The determination of perceived slant can be modeled as a weighted combination of three estimates based on those signals: a perspective estimate, a stereoscopic estimate based on HSR and VSR, and a stereoscopic estimate based on HSR and sensed eye position. In a series of experiments, we examined human observers ’ use of the two stereoscopic means of estimation. Perspective cues were rendered uninformative. We found that VSR and sensed eye position are both used to interpret the measured horizontal disparities. When the two are placed in conflict, the visual system usually gives more weight to VSR. However, when VSR is made difficult to measure by using short stimuli or stimuli composed of vertical lines, the visual system relies on sensed eye position. A model in which the observer’s slant estimate is a weighted average of the slant estimate based on HSR and VSR and the one based on HSR and eye position accounted well for the data. The weights varied across viewing conditions because the informativeness of the signals they employ vary from one