Three-Dimensional Scene Reconstruction

2011 ◽  
pp. 142-162
Author(s):  
Dimitrios Chrysostomou ◽  
Antonios Gasteratos
Keyword(s):  
Vision System ◽  
Three Dimensional ◽  
3D Models ◽  
Scene Reconstruction ◽  
Depth Information ◽  
Vision Systems ◽  
Working Space ◽  
Scene Structure ◽  
Long Time ◽  
Dimensional Surface

The production of 3D models has been a popular research topic already for a long time, and important progress has been made since the early days. During the last decades, vision systems have established to become the standard and one of the most efficient sensorial assets in industrial and everyday applications. Due to the fact that vision provides several vital attributes, many applications tend to use novel vision systems into domestic, working, industrial, and any other environments. To achieve such goals, a vision system should robustly and effectively reconstruct the 3D surface and the working space. This chapter discusses different methods for capturing the three-dimensional surface of a scene. Geometric approaches to three-dimensional scene reconstruction are generally based on the knowledge of the scene structure from the camera’s internal and external parameters. Another class of methods encompasses the photometric approaches, which evaluate the pixels’ intensity to understand the three-dimensional scene structure. The third and final category of approaches, the so-called real aperture approaches, includes methods that use the physical properties of the visual sensors for image acquisition in order to reproduce the depth information of a scene.

A Liberating Experience. On Becoming a Work of Art

2020 ◽  
Vol 7 (2) ◽  
pp. 411-430
Author(s):  
Maja Tabea Jerrentrup
Keyword(s):  
Three Dimensional ◽  
The Body ◽  
The Other ◽  
Work Of Art ◽  
Other Hand ◽  
Film Clips ◽  
Long Time ◽  
The One ◽  
Body Painting ◽  
Dimensional Surface

Abstract The art of bodypainting that is fairly unknown to a wider public turns the body into a canvas - it is a frequently used phrase in the field of bodypainting that illustrates the challenge it faces: it uses a three-dimensional surface and has to cope with its irregularities, but also with the model’s abilities and characteristics. This paper looks at individuals who are turned into art by bodypainting. Although body painting can be very challenging for them - they have to expose their bodies and to stand still for a long time while getting transformed - models report that they enjoy both the process and the result, even if they are not confident about their own bodies. Among the reasons there are physical aspects like the sensual enjoyment, but also the feeling of being part of something artistic. This is enhanced and preserved through double staging - becoming a threedimentional work of art and then being staged for photography or film clips. This process gives the model the chance to experience their own body in a detached way. On the one hand, bodypainting closely relates to the body and on the other hand, it can help to over-come the body.

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.

Research on Cotton Row Detection Algorithm Based on Binocular Vision

2014 ◽  
Vol 670-671 ◽  
pp. 1222-1227 ◽  
Author(s):  
Zhong Xiang Zhu ◽  
Yan He ◽  
Zhi Qiang Zhai ◽  
Jin Yi Liu ◽  
En Rong Mao
Keyword(s):  
Stereo Vision ◽  
Vision System ◽  
Three Dimensional ◽  
Measuring Method ◽  
Detection Algorithm ◽  
High Accuracy ◽  
Depth Information ◽  
Automatic Navigation ◽  
Binocular Stereo Vision ◽  
Binocular Stereo

As a relative locating method, machine vision is generally used for automatic navigation of cotton cultivator or cotton insecticide sprayer. However, it is difficult to achieve reliable and stable recognition of crop row with monocular stereo vision system, because it neither can access directly to the depth information of the image, which leads to massive time-consuming calculation, nor possess high-accuracy recognition or a good anti-noise property. This paper presents an algorithm for cotton row detection based on binocular stereo vision to be used for automatic navigation of cotton cultivator. The Zhang's plane calibration is used to obtain the internal and external parameters of the binocular stereo vision. Preprocessing means are applied to distinguish the cotton from soil, stereoscopic match is conducted according to the SIFT operators after the preprocessing of images, after which cotton space three-dimensional coordinates are acquired by parallax distance measuring method, with the elevation information combination of Hough transform, cotton lines are finally detected. The detection results indicate that this method has an accuracy higher than 90%, which primarily meets the need of automatic navigation for cotton cultivator.

scholarly journals Key Aspects in 3D Fatigue Crack Closure Numerical Modelling

2018 ◽  
Vol 774 ◽  
pp. 441-446 ◽  
Author(s):  
Antonio González-Herrera ◽  
Daniel Camas ◽  
J. Garcia-Manrique
Keyword(s):  
Fatigue Crack ◽  
Numerical Modelling ◽  
Crack Closure ◽  
Three Dimensional ◽  
3D Models ◽  
Fatigue Crack Closure ◽  
Long Time ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Key Aspects

Since long time, fatigue crack closure has been studied by means of finite element models. Initially by bi-dimensional models and recently, due to the higher computational capabilities, the use of three-dimensional models has been extended, providing a wider comprehension of the problem. Starting with the methodology used for 2D cases, a specific methodology for 3D models has been developed. Key parameters affecting the model have been analyzed and recommendations have been established. The numerical accuracy is evaluated in terms of crack closure and opening values. They main issues studied are the material behaviour, the loading cycles and crack growth scheme, the contact simulation, the meshing and the element size at the crack tip and along the thickness, the plastic wake computed and the opening and closure definition considered. This paper summarises the main learning and recommendations from the latest numerical modelling experience of the authors.

scholarly journals Design and Workspace Analysis of a Differential Motion Rotary Style Breast Interventional Robot

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yongde Zhang ◽  
Liyi Sun ◽  
Dexian Liang ◽  
Haiyan Du
Keyword(s):  
Physical Model ◽  
Interventional Procedure ◽  
Three Dimensional ◽  
Hydraulic Drive ◽  
Positioning Error ◽  
Three Dimensional Model ◽  
Differential Motion ◽  
Working Space ◽  
Control Research ◽  
Long Time

Introduction. Magnetic Resonance Imaging has better resolution for soft tissue; at the same time, the robot can work in a stable manner for a long time. MRI image-guided breast interventional robots have attracted much attention due to their minimally invasive nature and accuracy. In this paper, a hydraulic-driven MRI-compatible breast interventional robot is proposed to perform breast interventional procedure. Methods. First is the analysis of the design requirements of the hydraulic-driven MRI-compatible breast interventional robot, and then the design scheme is determined. Second, the three-dimensional model and the link frames are established. The workspace of the robot end point is solved by MATLAB/Simulink software. Then, the 3D printing technology is used to make a physical model of the MRI-compatible breast interventional robot. After assembly and debugging, the physical model is used for workspace verification, and the simulation result of the workspace shows that it is correct. Finally, the experimental research on the positioning error of the hydraulic drive is carried out, which established the theoretical foundation for the follow-up control research of the robot. Results. The positioning error has nothing to do with the motion distance, speed, and length of the selected tubing. The errors are 0.564 mm, 0.534 mm, and 0.533 mm at different distances of 40 mm, 80 mm, and 120 mm, respectively. The errors are 0.552 mm, 0.564 mm, and 0.559 mm at different speeds of 3 mm/s, 5 mm/s, and 8 mm/s, respectively. The errors are 0.564 mm, 0.568 mm, and 0.548 mm for different lengths of 0.5 m, 1 m, and 1.6 m, respectively. Then, the robot’s working space on the X O Z plane and the X O Y plane meets the conditions. Conclusion. The structure of a differential rotary breast interventional robot is determined, with the link frames assigned to the mechanism and the Denavit-Hartenberg parameters given. Workspace simulation of MRI-compatible breast interventional robot is done in MATLAB. The 3D printed MRI-compatible breast interventional robot is assembled and debugged to verify that its working space and positioning error meet the requirements.

scholarly journals A flexible ultrasensitive optoelectronic sensor array for neuromorphic vision systems

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qian-Bing Zhu ◽  
Bo Li ◽  
Dan-Dan Yang ◽  
Chi Liu ◽  
Shun Feng ◽  
...  
Keyword(s):  
Sensor Array ◽  
Vision System ◽  
Vision Systems ◽  
Neuromorphic Circuits ◽  
Image Sensing ◽  
Perovskite Quantum Dots ◽  
Optoelectronic Sensor ◽  
Weak Light ◽  
Do So ◽  
Neuromorphic Vision

AbstractThe challenges of developing neuromorphic vision systems inspired by the human eye come not only from how to recreate the flexibility, sophistication, and adaptability of animal systems, but also how to do so with computational efficiency and elegance. Similar to biological systems, these neuromorphic circuits integrate functions of image sensing, memory and processing into the device, and process continuous analog brightness signal in real-time. High-integration, flexibility and ultra-sensitivity are essential for practical artificial vision systems that attempt to emulate biological processing. Here, we present a flexible optoelectronic sensor array of 1024 pixels using a combination of carbon nanotubes and perovskite quantum dots as active materials for an efficient neuromorphic vision system. The device has an extraordinary sensitivity to light with a responsivity of 5.1 × 107 A/W and a specific detectivity of 2 × 1016 Jones, and demonstrates neuromorphic reinforcement learning by training the sensor array with a weak light pulse of 1 μW/cm2.

Effects of Velvet Antler Polypeptide-Collagen/Chitosan Materials on Proliferation of Osteoblast

2013 ◽  
Vol 380-384 ◽  
pp. 4295-4298
Author(s):  
Wen He Zhu ◽  
Jun Jie Xu ◽  
Wei Zhang ◽  
Yan Li ◽  
Xiao Jing Lu ◽  
...  
Keyword(s):  
Drug Treatment ◽  
Bone Defect ◽  
Three Dimensional ◽  
Chitosan Scaffold ◽  
Release Drug ◽  
Dimensional Network ◽  
Velvet Antler ◽  
Result Show ◽  
Long Time ◽  
Velvet Antler Polypeptide

A highly osteogenic hybrid bioabsorbable scaffold was developed for bone reconstruction. Though the use of a bioabsorbable collagen and chitosan scaffold for loading velvet antler polypeptide to repair bone defect and drug treatment. Velvet antler polypeptide and collagen were extracted for developing the compounded material. The SEM results show that the collagen and chitosan scaffold maintain the natural three dimensional network structures. The cell proliferation experiment result show that the can promote the osteoblast proliferation for a long time . These results indicated that this compound scaffold can sustainable to release drug and is a good material in bone defect and drug treatment.

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