Surface Contours, Glass Patterns, and a Slant Illusion

Perception ◽  
1986 ◽  
Vol 15 (5) ◽  
pp. 537-540 ◽  
Author(s):  
David C Earle
Keyword(s):  
Three Dimensional ◽  
Surface Shape ◽  
Surface Contour ◽  
Contour Pattern ◽  
Contour Information ◽  
Glass Patterns ◽  
Dimensional Surface

A surface contour pattern constructed from continuous sine waves is subject to several visual interpretations, whereby the separate regions containing the maxima and the minima of the sine waves may be seen as representing either convex or concave areas of a three-dimensional surface. In a pattern of segments of contours comprising only the regions containing the maxima and minima of the sine waves, a set of surfaces is perceived, each of which tends to be seen as convex, and which possesses an illusory slant which is different for columns of contour segments containing maxima as compared with columns containing minima. It is conjectured that the slant illusion is a manifestation of the processes by which depth is derived from surface contour information. It is demonstrated that corresponding figures constructed from sinusoidal Glass patterns produce similar effects. From this it is concluded that the structure of Glass patterns provides a sufficient input representation for the processes by which surface shape is recovered from surface contours.

Paper 3: Non-Contact Surface Contour Analyser

1967 ◽  
Vol 182 (11) ◽  
pp. 360-367 ◽  
Author(s):  
B. E. Keller
Keyword(s):  
Contact Surface ◽  
Surface Condition ◽  
Three Dimensional ◽  
Light Spot ◽  
Test Surface ◽  
Basic Technique ◽  
Surface Contour ◽  
Data Points ◽  
Dimensional Surface

This paper describes the development of an accurate and rapid non-contact technique for numerically defining three-dimensional surface contour. Because the basic technique uses a diffusely reflected spot of light on the test surface to define surface position, considerable attention is given to surface condition variables which influence the ability and effectiveness of following a moving light spot on a test surface. Methods for transforming data points representative of surface contour into a practical form satisfying engineering and inspection requirements are also discussed.

EVALUATION FOR RESIDUAL AXIAL FORCE OF CORRODED HIGH TENSILE BOLTS

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Ryoichi Satake ◽  
Katashi Fujii ◽  
Yumi Mori
Keyword(s):  
Axial Force ◽  
Three Dimensional ◽  
High Strength ◽  
Surface Shape ◽  
Thickness Reduction ◽  
Long Time ◽  
Force Reduction ◽  
The Relationship ◽  
Dimensional Surface

This paper presents a method for evaluating the residual axial force of corroded high strength bolts in experiments, and analysis measuring the axial force of corroded high strength bolts. In order to reproduce the axial force reduction due to corrosion, the test specimens were made by cutting the bolt head widthwise or the height-wise with an initial axial force. The curve of axial force lowering is prepared with a reduced thickness in height and width of bolts as a parameter. Therefore, the residual axial force can be estimated by the thickness reduction of bolt. Moreover, we measured the residual axle force of real corroded high strength bolts, taken from a bridge removed from service for a long time, and inspected an axis drop curve. In order to classify corrosion shapes, we measured the three-dimensional surface shape of corroded high strength bolts without contact, and considered the relationship between the surface shape of corroded high strength bolts and the axial force reduction.

Development of Infants' Sensitivity to Surface Contour Information for Spatial Layout

Perception ◽  
10.1068/p2789 ◽  
2001 ◽  
Vol 30 (2) ◽  
pp. 167-176 ◽  
Author(s):  
Maya G Sen ◽  
Albert Yonas ◽  
David C Knill
Keyword(s):  
Age Groups ◽  
Spatial Layout ◽  
The Other ◽  
Surface Shape ◽  
Depth Information ◽  
Surface Contour ◽  
Depth Cue ◽  
Contour Information ◽  
Monocular Depth ◽  
Control Study

The development of sensitivity to a recently discovered static-monocular depth cue to surface shape, surface contours, was investigated. Twenty infants in each of three age groups (5, 5½, and 7 months) viewed a display that creates an illusion, for adult viewers, that what is in fact a frontoparallel cylinder is slanted away in depth, so that one end appears closer than the other. Preferential reaching was recorded in both monocular and binocular conditions. More reaching to the apparently closer end in the monocular than in the binocular condition is evidence of sensitivity. Infants aged 7 months responded to surface contour information, but infants aged 5 and 5 months did not. In a control study, twenty 5-month-old infants reached consistently for the closer ends of cylinders that were actually rotated in depth. As findings with other static-monocular depth information suggest, infants' sensitivity to surface contour information appears to develop at approximately 6 months.

Three-Dimensional Surface Shape Measurement of Big Objects by Image Splicing in Digital Holography

2008 ◽  
Vol 35 (12) ◽  
pp. 2017-2021 ◽  
Author(s):  
冯忠耀 Feng Zhongyao ◽  
贾昉 Jia Fang ◽  
周景会 Zhou Jinghui ◽  
忽满利 Hu Manli
Keyword(s):  
Digital Holography ◽  
Three Dimensional ◽  
Surface Shape ◽  
Shape Measurement ◽  
Image Splicing ◽  
Dimensional Surface
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