Visual perception of surface curvature: Psychophysics of curvature detection induced by motion parallax

Valérie Cornilleau-Pérès; Jacques Droulez

doi:10.3758/bf03204989

Visual perception of surface curvature: Psychophysics of curvature detection induced by motion parallax

Perception & Psychophysics ◽

10.3758/bf03204989 ◽

1989 ◽

Vol 46 (4) ◽

pp. 351-364 ◽

Cited By ~ 32

Author(s):

Valérie Cornilleau-Pérès ◽

Jacques Droulez

Keyword(s):

Visual Perception ◽

Motion Parallax ◽

Surface Curvature ◽

Curvature Detection

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Depth Capture by Kinetic Depth and by Stereopsis

Perception ◽

10.1068/p3011 ◽

2000 ◽

Vol 29 (2) ◽

pp. 211-220 ◽

Cited By ~ 6

Author(s):

Keetaek Kham ◽

Randolph Blake

Keyword(s):

Surface Structure ◽

Motion Parallax ◽

Surface Curvature ◽

Direction Parallel ◽

Object A ◽

Kinetic Depth ◽

Motion Flow

The perceived depth of regions within a stereogram lacking explicit disparity information can be captured by the surface structure of regions where disparity is explicit: stereo capture. In two experiments, observers estimated surface curvature/depth of an untextured object (a ‘ribbon’) superimposed on a cylinder textured with dots, the cylinder curvature being defined by disparity (stereo depth) or by motion parallax (kinetic depth: KD). With the stereo-defined cylinder, depth capture was obtained under conditions where the disparity of the ribbon was ambiguous; with the KD, cylinder depth capture was obtained under conditions where the motion flow of the cylinder was in a direction parallel to that of the ribbon. These results demonstrate yet another similarity between KD and stereopsis.

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Visual perception of surface curvature. The spin variation and its physiological implications

Biological Cybernetics ◽

10.1007/bf00198096 ◽

1990 ◽

Vol 62 (3) ◽

pp. 211-224 ◽

Cited By ~ 35

Author(s):

J. Droulez ◽

V. Cornilleau-Pérès

Keyword(s):

Visual Perception ◽

Surface Curvature

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Correlations Between Body Angles and Substrate Curvature in the Parasitoid Wasp Trichogramma Minutum: A Possible Mechanism of Host Radius Measurement

Journal of Experimental Biology ◽

10.1242/jeb.125.1.271 ◽

1986 ◽

Vol 125 (1) ◽

pp. 271-285 ◽

Cited By ~ 2

Author(s):

J. M. Schmidt ◽

J. J.B. Smith

Keyword(s):

Parasitoid Wasp ◽

Surface Curvature ◽

The Body ◽

Host Recognition ◽

Host Acceptance ◽

Body Parts ◽

Trichogramma Minutum ◽

Curvature Detection ◽

Curvature Measurements ◽

Different Diameters

The parasitoid wasps of the genus Trichogramma use the surface curvature of their insect egg hosts to set an upper limit to the number of progeny allocated to the host, as well as the duration of their host examination. In addition, host recognition and host acceptance are in part mediated by surface curvature. In this paper, the relationships between the positions of body parts of the wasp and surface curvature are examined in order to determine a possible mechanism for curvature detection by the wasp. Wasps of different sizes were photographed in profile while examining glass bead models of different diameters. The positions of selected body parts were analysed using a digitizer and microcomputer. The height of the wasp above the model surface did not change with surface curvature. Furthermore, the angle of the head relative to the thorax was also constant over the range of models used. Only the scapal-head angle and flagellar-head angle changed significantly with surface curvature. A curvature detecting mechanism is proposed in which the wasp uses the scapal-head angle to measure the curvature of the surface. The body of the wasp is maintained at a preferred height and angle to the substrate, serving as a fixed platform from which curvature measurements are made. Additional features of this mechanism, as well as its correlation with morphological and behavioural findings, are discussed.

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