scholarly journals Reconstructing the Three-Dimensional Point Cloud of a Draped Fabric Based On a Two-Dimensional Projection

2021 ◽  
Vol 11 (6) ◽  
pp. 413-417
Author(s):  
Zhicai Yu ◽  
◽  
Yueqi Zhong ◽  
Haoyang Xie
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Two Dimensional

scholarly journals Evaluations on The Use Of 3d Terrestrial Laser Scanning Technology in Architectural Conservation Projects

2021 ◽  
Author(s):  
Saadet Armağan Güleç Korumaz ◽  
◽  
Büşra Kubiloğlu ◽  
Keyword(s):  
Cultural Heritage ◽  
Point Cloud ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Terrestrial Laser Scanning ◽  
Field Studies ◽  
High Accuracy ◽  
Two Dimensional ◽  
Conservation Projects ◽  
Architectural Documentation

3D Laser Scanning technologies have proven to be significant way to architectural documentation studies. Due to these facilities, the use of technology in architectural documentation have become widespread day by day. Thanks to these technologies it is possible to get high accuracy and intense data in a short time compared to conventional methods. Therefore, this technology has increased the content and quality of conservation practices. The technology is mainly aimed at obtaining a three-dimensional model or two-dimensional layouts from a dense and detailed point cloud. Terrestrial Laser Scanning (TLS) does not only support simple CAD-based conservation projects, but also allows obtaining high-resolution plane pictures, art tours, three-dimensional mesh models, and two-dimensional maps. Besides these possibilities, high accuracy data on the morphological properties of the documented object can be obtained as a result of the analyses including point cloud. On the other hand, the technology gives possibility data to be shared in different environments and filtered data can be used online. Thus, different disciplines are able to easily access information. These features of technology add a different dimension to the studies in the field of cultural heritage and contribute to the digitalization of the heritage. In the scope of this study, evaluations are made regarding the innovations and usage possibilities brought by TLS technology to architectural documentation field based on the cultural heritage samples. In addition, within the scope of the study, trials were made on field studies for parameters that will affect data quality, accuracy and speed. In addition, within the scope of the study, some tests were made on field studies for parameters affecting data quality, accuracy and speed. With the obtained results, evaluations have been made to increase the usage potential of the technology today.

The Method and Implementation of Three-Dimensional Laser Scanning Pipeline Scan Data Outliers Excluded

2013 ◽  
Vol 864-867 ◽  
pp. 2760-2763
Author(s):  
Zhi Liang Li ◽  
He Sheng Zhang ◽  
Qi Wu
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Handling Characteristics ◽  
Gross Error ◽  
Error Elimination ◽  
Scan Data

This article is based on three-dimensional laser scanning technology for the modeling of a chemical plant piping, scanned point cloud data with a lot of blunders, comprehensive analysis of the point cloud handling characteristics and stage of maturity of two-dimensional graphics. As a result, a concept of transforming the point cloud data with three dimensional to two-dimensional is formed. Then, according to point and circle positional relationship in the same plane, derived an Algorithm about Gross Error Elimination, finally, programming and achieve it.

A STUDY OF DENTAL 3D POINTS CLOUD MEASUREMENT SYSTEM BASED ON GRATING PROJECTION

2013 ◽  
Vol 13 (06) ◽  
pp. 1340019
Author(s):  
QINMIAO ZHU ◽  
MOUHU WU ◽  
XINDA HUANG ◽  
BO TAO
Keyword(s):  
Measurement System ◽  
Point Cloud ◽  
Clinical Medicine ◽  
Three Dimensional ◽  
Phase Unwrapping ◽  
Analysis Tool ◽  
Two Dimensional ◽  
3D Point Cloud ◽  
Dimensional Image ◽  
Two Dimensional Image

A novel non-contact dental 3D points cloud measurement system based on grating projection is proposed in this paper. The system has the key functions of calibration, phase unwrapping and conversion of two-dimensional image to the 3D point cloud and so on, and it can provide three-dimensional graphics of the dental wax with rotations and translation to observe and measure the various parts of dental wax surface. The system can be used as a useful test and analysis tool for clinical medicine teaching and researches.

scholarly journals Two-Dimensional LiDAR Sensor-Based Three-Dimensional Point Cloud Modeling Method for Identification of Anomalies inside Tube Structures for Future Hypersonic Transportation

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7235
Author(s):  
Jongdae Baek
Keyword(s):  
Anomaly Detection ◽  
Point Cloud ◽  
Detection System ◽  
Three Dimensional ◽  
Transportation System ◽  
Transportation Infrastructure ◽  
Two Dimensional ◽  
3D Point Cloud ◽  
Next Generation ◽  
Cloud Models

The hyperloop transportation system has emerged as an innovative next-generation transportation system. In this system, a capsule-type vehicle inside a sealed near-vacuum tube moves at 1000 km/h or more. Not only must this transport tube span over long distances, but it must be clear of potential hazards to vehicles traveling at high speeds inside the tube. Therefore, an automated infrastructure anomaly detection system is essential. This study sought to confirm the applicability of advanced sensing technology such as Light Detection and Ranging (LiDAR) in the automatic anomaly detection of next-generation transportation infrastructure such as hyperloops. To this end, a prototype two-dimensional LiDAR sensor was constructed and used to generate three-dimensional (3D) point cloud models of a tube facility. A technique for detecting abnormal conditions or obstacles in the facility was used, which involved comparing the models and determining the changes. The design and development process of the 3D safety monitoring system using 3D point cloud models and the analytical results of experimental data using this system are presented. The tests on the developed system demonstrated that anomalies such as a 25 mm change in position were accurately detected. Thus, we confirm the applicability of the developed system in next-generation transportation infrastructure.

scholarly journals STRATEGIES TO EVALUATE THE VISIBILITY ALONG AN INDOOR PATH IN A POINT CLOUD REPRESENTATION

2017 ◽  
Vol IV-2/W4 ◽  
pp. 311-317 ◽  
Author(s):  
N. Grasso ◽  
E. Verbree ◽  
S. Zlatanova ◽  
M. Piras
Keyword(s):  
Visual Perception ◽  
Point Cloud ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Space Syntax ◽  
Point Of View ◽  
Indoor Environments ◽  
Two Dimensional ◽  
Visibility Graphs ◽  
Representations Of Space

Many research works have been oriented to the formulation of different algorithms for estimating the paths in indoor environments from three-dimensional representations of space. The architectural configuration, the actions that take place within it, and the location of some objects in the space influence the paths along which is it possible to move, as they may cause visibility problems. To overcome the visibility issue, different methods have been proposed which allow to identify the visible areas and from a certain point of view, but often they do not take into account the user’s visual perception of the environment and not allow estimating how much may be complicated to follow a certain path. In the field of space syntax and cognitive science, it has been attempted to describe the characteristics of a building or an urban environment by the isovists and visibility graphs methods; some numerical properties of these representations allow to describe the space as for how it is perceived by a user. However, most of these studies are directed to analyze the environment in a two-dimensional space. In this paper we propose a method to evaluate in a quantitative way the complexity of a certain path within an environment represented by a three-dimensional point cloud, by the combination of some of the previously mentioned techniques, considering the space visible from a certain point of view, depending on the moving agent (pedestrian , people in wheelchairs, UAV, UGV, robot).

scholarly journals Reconstruction of Two-dimensional Image to Three-dimensional Point Cloud Data for Detection of Empty Rot Defects in Tree Growth

CONVERTER ◽  
2021 ◽  
pp. 459-470
Author(s):  
Shufeng Jiang, Keqi Wang
Keyword(s):  
Point Cloud ◽  
Color Space ◽  
Three Dimensional ◽  
Boundary Curve ◽  
Data Reconstruction ◽  
Two Dimensional ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Extraction Algorithm ◽  
Radar Wave

In the application of nondestructive detecting of trees, it is a technical problem to use radar waves to detect tree specimens with growth defects, how to segment defect areas after obtaining two-dimensional images, and reverse simulate the detection results with three-dimensional point cloud data. Therefore, the method of extracting boundary information according to color features is studied to extract the boundary curve of empty rot area, and the selection of higher precision extraction algorithm is determined by comparing the boundary extraction results of HSV color space and RGB color space in laboratory According to the extracted void boundary curve, the reverse modeling is carried out, and the mapping from 2D inspection gray image to 3D space is realized, The point cloud data reconstruction needed for 3D modeling of multi-curved surfaces is obtained in reverse. The boundary curve extraction algorithm in this study is used to process the images of nondestructive testing of trees. Through comparative experiments and error analysis, the accurate modeling conclusion from inversion of 2D images to 3D point cloud data reconstruction by radar wave detection is verified, and the Core issue problem of point cloud reconstruction in the ill-conditioned area of tree growth and decay detected by radar wave is solved.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Instrumentation For Quantitative Microscopy

1977 ◽  
Vol 35 ◽  
pp. 206-209
Author(s):  
B. Ralph ◽  
A.R. Jones
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Automatic Data ◽  
Phase Volume Fraction ◽  
Statistical Confidence ◽  
Resultant Data ◽  
Automatic Data Collection ◽  
Third Dimension ◽  
Evolution Of Microstructure

In all fields of microscopy there is an increasing interest in the quantification of microstructure. This interest may stem from a desire to establish quality control parameters or may have a more fundamental requirement involving the derivation of parameters which partially or completely define the three dimensional nature of the microstructure. This latter categorey of study may arise from an interest in the evolution of microstructure or from a desire to generate detailed property/microstructure relationships. In the more fundamental studies some convolution of two-dimensional data into the third dimension (stereological analysis) will be necessary.In some cases the two-dimensional data may be acquired relatively easily without recourse to automatic data collection and further, it may prove possible to perform the data reduction and analysis relatively easily. In such cases the only recourse to machines may well be in establishing the statistical confidence of the resultant data. Such relatively straightforward studies tend to result from acquiring data on the whole assemblage of features making up the microstructure. In this field data mode, when parameters such as phase volume fraction, mean size etc. are sought, the main case for resorting to automation is in order to perform repetitive analyses since each analysis is relatively easily performed.

A linearity test for thick specimens imaged by HVEM over a 180° angular range

1991 ◽  
Vol 49 ◽  
pp. 552-553
Author(s):  
Yu Liu
Keyword(s):  
Phase Contrast ◽  
Three Dimensional ◽  
Angular Range ◽  
Two Dimensional ◽  
Back Projection ◽  
Line Integral ◽  
Exponential Law ◽  
Transmission Electron ◽  
Absorption Law ◽  
Linearity Test

The image obtained in a transmission electron microscope is the two-dimensional projection of a three-dimensional (3D) object. The 3D reconstruction of the object can be calculated from a series of projections by back-projection, but this algorithm assumes that the image is linearly related to a line integral of the object function. However, there are two kinds of contrast in electron microscopy, scattering and phase contrast, of which only the latter is linear with the optical density (OD) in the micrograph. Therefore the OD can be used as a measure of the projection only for thin specimens where phase contrast dominates the image. For thick specimens, where scattering contrast predominates, an exponential absorption law holds, and a logarithm of OD must be used. However, for large thicknesses, the simple exponential law might break down due to multiple and inelastic scattering.

An Image Reconstruction System Applied to High Voltage Microscopy

1975 ◽  
Vol 33 ◽  
pp. 292-293
Author(s):  
D. E. Johnson
Keyword(s):  
High Voltage ◽  
Prior Information ◽  
Block Diagram ◽  
Three Dimensional ◽  
Real Space ◽  
Two Dimensional ◽  
Efficient Manner ◽  
Fourier Methods ◽  
Tilt Series ◽  
Methods Of Reconstruction

Increased specimen penetration; the principle advantage of high voltage microscopy, is accompanied by an increased need to utilize information on three dimensional specimen structure available in the form of two dimensional projections (i.e. micrographs). We are engaged in a program to develop methods which allow the maximum use of information contained in a through tilt series of micrographs to determine three dimensional speciman structure.In general, we are dealing with structures lacking in symmetry and with projections available from only a limited span of angles (±60°). For these reasons, we must make maximum use of any prior information available about the specimen. To do this in the most efficient manner, we have concentrated on iterative, real space methods rather than Fourier methods of reconstruction. The particular iterative algorithm we have developed is given in detail in ref. 3. A block diagram of the complete reconstruction system is shown in fig. 1.

Sign in / Sign up

Export Citation Format

Share Document