The role of perspective effects and accelerations in perceived three-dimensional structure-from-motion.

Hogervorst, Maarten A.; Eagle, Richard A

doi:10.1037/0096-1523.26.3.934

Cited by 15 publications

(16 citation statements)

References 47 publications

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“…This would require information about the threedimensional motion of the object (in this case, its speed of rotation). Such information is available only by considering either spatial or temporal variations in velocity; perceptual studies have shown that we cannot readily utilize this information (42) and a similar picture may be true here also.…”

Section: The Use Of Binocular and Motion Cues To Scale Prehensionmentioning

confidence: 97%

Reaching for virtual objects: binocular disparity, retinal motion and the control of prehension

Bradshaw¹,

Hibbard²

2003

Arq. Bras. Oftalmol.

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Section: The Use Of Binocular and Motion Cues To Scale Prehensionmentioning

confidence: 97%

Reaching for virtual objects: binocular disparity, retinal motion and the control of prehension

Bradshaw¹,

Hibbard²

2003

Arq. Bras. Oftalmol.

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“…A veridical description of the Euclidean structure of an object can be derived from second-order optic flow, if appropriate assumptions are introduced in the interpretation process (Longuet-Higgins & Prazdny, 1980;Ullman, 1979). It has been shown, however, that human observers have a very limited sensitivity for the second-order temporal properties of the optic flow and thus rely mainly on velocities to recover 3D information (Hogervorst & Eagle, 2000;Todd & Bressan, 1990). If only the first-order information is used, however, it is not possible, in principle, to derive a veridical estimate of depth.…”

Section: Perceived Depth From Velocity Signalsmentioning

confidence: 99%

Matching perceived depth from disparity and from velocity: Modeling and psychophysics

Domini

Caudek

2010

Acta Psychologica

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a b s t r a c tWe asked observers to match in depth a disparity-only stimulus with a velocity-only stimulus. The observers' responses revealed systematic biases: the two stimuli appeared to be matched in depth when they were produced by the projection of different distal depth extents. We discuss two alternative models of depth recovery that could account for these results. (1) Depth matches could be obtained by scaling the image signals by constants not specified by optical information, and (2) depth matches could be obtained by equating the stimuli in terms of their signal-to-noise ratios (see Domini & Caudek, 2009). We show that the systematic failures of shape constancy revealed by observers' judgments are well accounted for by the hypothesis that the apparent depth of a stimulus is determined by the magnitude of the retinal signals relative to the uncertainty (i.e., internal noise) arising from the measurement of those signals.

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“…However, Perotti et al's (1996) displays were generated using orthographic projection (i.e., parallel perspective). Subsequently, Blair, Wickelgren, and Bingham (2001) investigated whether orthographic projection is a good model of perspective for other than small angle vision ( 4º of visual angle; see also Börjesson & Lind, 1996;Eagle & Hogervorst, 1999;Hogervorst & Eagle, 2000). They found that observers rotated or not.…”

Section: Methodsmentioning

confidence: 99%

Large continuous perspective transformations are necessary and sufficient for accurate perception of metric shape

Bingham

Lind

2008

Perception & Psychophysics

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524Object shape entails both qualitative and quantitative properties. On the one hand, shape entails relief structure or relative variations in the surface conformation (e.g., ellipsoidal vs. cylindrical). As has been described by Perotti, Todd, Lappin, and Phillips (1998), this characteristic of shape can be measured locally for smoothly curved surfaces by the shape characteristic, a ratio of the principal curvatures. On the other hand, metric shape can be measured by curvedness (Koenderink, 1990) or, alternatively, the ratio of an object's width to its depth. As has been reviewed by Todd, Tittle, and Norman (1995) and shown by Perotti et al. (1998), among many others (e.g., Brenner & van Damme, 1999;Lappin & Ahlström, 1994;Scarfe & Hibbard, 2006;Tittle, Todd, Perotti, & Norman, 1995;Todd & Norman, 1991), observers do not appear to be able to perceive metric shape, or the relative depth of objects, very accurately. Perotti et al. (1998), in particular, found that observers were well able to judge the shape characteristic but that judgments of curvedness were biased and highly variable. These studies involved structure from motion or stereo computer graphic displays of objects. Lind, Bingham, and Forsell (2003) asked observers to judge the shape of textured wooden cylinders-that is, actual objects that were about 7 cm in size. Aspect ratios (depth/width [D/W ]) between 0.46 and 1.81 were tested. Observers used binocular vision with free head movement in normal lighting, and the objects sat on a tabletop within reach distance, so that the tops of the objects could be seen. The participants adjusted the shape of an elliptical outline on a computer screen to match the perceived cross-sectional shape of each object. The results were much like those in Perotti et al. (1998). Judgments were highly variable and inaccurate. Lind et al. (2003) replicated the result with variations in viewing height and distance. The participants did not reliably begin to get it right until they were essentially looking straight down at the tops of the objects, so they could match their outline to the top edge of the cylinders appearing in a frontoparallel plane. It is clear that observers cannot judge metric shape under viewing conditions that allow only relatively small perspective variations ( 10º).There We investigated the ability to perceive the metric shape of elliptical cylinders. A large number of previous studies have shown that small perspective variations ( 10º) afforded by stereovision and by head movements fail to allow accurate perception of metric shape. If space perception is affine (Koenderink & van Doorn, 1991), observers are unable to compare or relate lengths in depth to frontoparallel lengths (i.e., widths). Frontoparallel lengths can be perceived correctly, whereas lengths in depth generally are not. We measured reaches to evaluate shape perception and investigated whether larger perspective variations would allow accurate perception of shape. In Experiment 1, we replicated previous results showing poor perception wi...

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The role of perspective effects and accelerations in perceived three-dimensional structure-from-motion.

Cited by 15 publications

References 47 publications

Reaching for virtual objects: binocular disparity, retinal motion and the control of prehension

Reaching for virtual objects: binocular disparity, retinal motion and the control of prehension

Matching perceived depth from disparity and from velocity: Modeling and psychophysics

Large continuous perspective transformations are necessary and sufficient for accurate perception of metric shape

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