Accuracy enhancement of three-dimensional surface shape measurement using curvelet transform

2014 ◽  
Author(s):  
Biyu Zhao ◽  
Huimin Yue ◽  
Yuxiang Wu ◽  
Zhonghua Ou ◽  
Yong Liu
Keyword(s):  
Three Dimensional ◽  
Curvelet Transform ◽  
Surface Shape ◽  
Shape Measurement ◽  
Accuracy Enhancement ◽  
Dimensional Surface

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

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.

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.

scholarly journals Crosscorrelation image processing for surface shape reconstruction using fiducial markers

2021 ◽  
Vol 2127 (1) ◽  
pp. 012030
Author(s):  
E V Shmatko ◽  
V V Pinchukov ◽  
A D Bogachev ◽  
A Yu Poroykov
Keyword(s):  
Correlation Function ◽  
Cross Correlation ◽  
Three Dimensional ◽  
Shape Reconstruction ◽  
Surface Shape ◽  
Optical Methods ◽  
Shape Measurement ◽  
Fiducial Markers ◽  
Correlation Processing ◽  
Function Calculation

Abstract Optical methods for deformations diagnostic and surface shape measurement are widely used in scientific research and industry. Most of these methods are based on triangulating a set of two-dimensional points in the images appropriate to the same three-dimensional points of the object in space. Various algorithms to search such points are applied. The possibility of using cross-correlation processing of digital images to search these points is considered in the work. Algorithms based on the correlation function calculation are widely employed in such a popular flow diagnostic method as PIV. The cameras of a stereo system for surface shape measurement can be widely spaced, and the tilt angles relative to the surface can differ significantly. This leads to the fact that the images taken from the cameras cannot be directly processed by the correlation function because it is not invariant to rotation. To solve this problem, fiducial markers are used to find an initial estimate of displacement of the images relative to each other. This approach makes it possible to successfully apply correlation processing for stereo system images with a large stereo base.

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