Representation of image surfaces by using curvature information

1998 ◽  
Author(s):  
Sheng-Jyh Wang ◽  
Jeng-Hong Twu ◽  
Hsi-Hsing Liu
Keyword(s):  
Curvature Information

Geometric Criteria for Gouge-Free Three-Axis Milling of Sculptured Surfaces

1998 ◽  
Author(s):  
Helmut Pottmann ◽  
Johannes Wallner ◽  
Georg Glaeser ◽  
Bahram Ravani
Keyword(s):  
Motion Planning ◽  
Sculptured Surfaces ◽  
Global Shape ◽  
Be Star ◽  
Offset Surfaces ◽  
Tool Motion ◽  
Curvature Information ◽  
Bivariate Functions

Abstract The paper presents a geometric investigation of collision-free 3-axis milling of surfaces. We consider surfaces with a global shape condition: they shall be interpretable as graphs of bivariate functions or shall be star-shaped with respect to a point. If those surfaces satisfy a local millability criterion involving curvature information, it is proved that this implies globally gouge-free milling. The proofs are based on general offset surfaces. The results can be applied to tool-motion planning and the computation of optimal cutter shapes.

scholarly journals Accelerating incremental gradient optimization with curvature information

2020 ◽  
Author(s):  
Hoi-To Wai ◽  
Wei Shi ◽  
César A. Uribe ◽  
Angelia Nedić ◽  
Anna Scaglione
Keyword(s):  
Gradient Optimization ◽  
Curvature Information

3D object recognition based on curvature information of planar views

2003 ◽  
Vol 36 (11) ◽  
pp. 2571-2584 ◽  
Author(s):  
C. de Trazegnies ◽  
C. Urdiales ◽  
A. Bandera ◽  
F. Sandoval
Keyword(s):  
Object Recognition ◽  
3D Object Recognition ◽  
3D Object ◽  
Curvature Information

Matching Geometric Shapes in 4D Space Incorporating Curvature Information

2007 ◽  
Author(s):  
Y. Song ◽  
J. S. M. Vergeest
Keyword(s):  
Extra Dimension ◽  
Shape Matching ◽  
Fine Tuning ◽  
Frequency Noise ◽  
Icp Algorithm ◽  
3 Dimensional ◽  
Additional Information ◽  
3D Space ◽  
Laplacian Smoothing ◽  
Curvature Information

The Iterative Closest Point (ICP) algorithm and its variants are widely used in matching different patches of 3-Dimensional (3D) scanning data. In this paper, a 4-Dimensional (4D) based approach is proposed to improve the robustness of the ICP algorithm. Considering curvatures of the given geometries as an extra dimension, the existing ICP algorithm can be extended to 4D space. The reason of using this additional information is that it introduces an extra dimension of similarity in the shape matching algorithm, thus improves the effectiveness of the optimization process. Using a variant of the Laplacian smoothing tool, high frequency noise and interferences in the curvature domain are suppressed and the principal geometric features are addressed. By a 4D to 3D orthogonal projection, the matched geometries are projected back to 3D space, where the existing ICP algorithm in 3D is applied as a fine-tuning tool. Numerical implementations on several sets of scanning data demonstrate the robustness of the proposed method. The converging process and the speed of the propose method are investigated as well.

Dotted Raster-Stereography

2018 ◽  
pp. 166-179
Author(s):  
Muhammad Wasim ◽  
Fauzan Saeed ◽  
Abdul Aziz ◽  
Adnan Ahmed Siddiqui
Keyword(s):  
Human Body ◽  
Practical Aspect ◽  
X Rays ◽  
Non Invasive ◽  
The Face ◽  
3D Surface Topography ◽  
The Subject ◽  
Human Faces ◽  
Curvature Information ◽  
Raster Pattern

Raster-stereography is a 3D surface topography technique, which provide height and curvature information of the subject. This is a non-contact, non-invasive and radiation free technique, which is mostly used to analyze the back shape of human body. The most practical aspect of raster-stereography is ease in its apparatus setup and reduced exposure to x-rays. Another very important and effective application is to identify the human faces that can be used in security domain. The problem of breaking lines was observed while traversing the distorted raster pattern on human body. These breaks in raster pattern increased significantly when projected on the face. Computationally it becomes difficult to extract all valid curvatures of the human face. This problem was resolved using a modified dotted raster and the noise effect was reduced substantially. The dotted raster technique proved that it is by far the best option when compared with the conventional line grid.

scholarly journals Full-Scale Reconstruction for Transmission Line Galloping Curves Based on Attitudes Sensors

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Decheng Wu ◽  
Shizhong Yang ◽  
Lu Tao ◽  
Hailin Cao ◽  
Xiaoheng Tan ◽  
...  
Keyword(s):  
Transmission Line ◽  
Low Complexity ◽  
Mapping Method ◽  
Linear Mapping ◽  
Full Scale ◽  
Reconstruction Method ◽  
Timely Fashion ◽  
Strong Winds ◽  
Short Time ◽  
Curvature Information

Caused by strong winds or nonuniform icing, conductor galloping is one of the major hazards that should be monitored in a timely fashion. In this paper, we proposed a new full-scale reconstruction method for transmission line curves based on the attitude sensors that uses only the tangential information and arc-length constraint. Meanwhile, a comparatively low-complexity algorithm is presented: (1) quaternion rotation to generate the tangent vectors; (2) a modified B-spline global interpolation to evaluate the curvature information; and (3) a linear mapping method to correct reconstruction curves. Moreover, sensors placement method is put forward according to the galloping features. Finally, both simulation and experimental results demonstrate that the proposed method can accurately reconstruct the galloping curves in a relatively short time, which fulfills the requirement of the real-time galloping monitoring system.

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