scholarly journals A COMPARISON OF LASER AND STRUCTURED LIGHT SCANNING TECHNOLOGIES FOR ARCHAEOLOGICAL APPLICATIONS

2021 ◽  
Vol 13 (3) ◽  
pp. 111-116
Author(s):  
Nikolaos Papas ◽  
◽  
Konstantinos Tsongas ◽  
Dimitrios Karolidis ◽  
Dimitrios Tzetzis ◽  
...  
Keyword(s):  
Structured Light ◽  
Three Dimensional ◽  
3D Models ◽  
3D Scanning ◽  
Acquisition Time ◽  
Digital Reference ◽  
Scanning Time ◽  
Actual Equipment ◽  
Scan Data

Reverse engineering and in particular three-dimensional digitization have become an essential part of the documentation of archaeological findings. 3D scanning produces a high-precision digital reference document. The factors that influence the quality of the 3D scanned data are the scanned object’s surface colour, its glossiness and geometry, and the ambient light during the scanning process. However, the actual equipment and scanning technologies are of primary importance. The current paper presents a qualitative and quantitative comparison between two 3D scanning devices of different technologies; structured light 3D scanning and laser 3D scanning. The benchmark for this comparison is an ancient Roman vase from the city of Thessaloniki, Greece. The object was scanned with every possible setting on each scanner, but only one configuration of settings on each device was selected for the final comparison. The main criterion for the final selection of the two 3D models acquired with the use of the two technologies was the proximity in the number of points and polygons produced for digitally restoring the ancient vase in the best possible way. The results indicate important differences regarding the accuracy of the final digital model. The laser technology produced better accuracy but with a significant cost in scanning time and model data size. On the other hand, the structured light technology achieved the optimal combination of scanning quality and accuracy, along with reduced acquisition time of scan data.

scholarly journals Structured-light 3D scanning of exhibited historical clothing—a first-ever methodical trial and its results

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jerzy Montusiewicz ◽  
Marek Miłosz ◽  
Jacek Kęsik ◽  
Kamil Żyła
Keyword(s):  
Cultural Heritage ◽  
Information Technologies ◽  
Structured Light ◽  
Three Dimensional ◽  
3D Models ◽  
3D Scanning ◽  
Dimensional Representation ◽  
3D Scanner ◽  
Three Dimensional Representation ◽  
3D Scanners

AbstractHistorical costumes are part of cultural heritage. Unlike architectural monuments, they are very fragile, which exacerbates the problems of their protection and popularisation. A big help in this can be the digitisation of their appearance, preferably using modern techniques of three-dimensional representation (3D). The article presents the results of the search for examples and methodologies of implementing 3D scanning of exhibited historical clothes as well as the attendant problems. From a review of scientific literature it turns out that so far practically no one in the world has made any methodical attempts at scanning historical clothes using structured-light 3D scanners (SLS) and developing an appropriate methodology. The vast majority of methods for creating 3D models of clothes used photogrammetry and 3D modelling software. Therefore, an innovative approach was proposed to the problem of creating 3D models of exhibited historical clothes through their digitalisation by means of a 3D scanner using structural light technology. A proposal for the methodology of this process and concrete examples of its implementation and results are presented. The problems related to the scanning of 3D historical clothes are also described, as well as a proposal how to solve them or minimise their impact. The implementation of the methodology is presented on the example of scanning elements of the Emir of Bukhara's costume (Uzbekistan) from the end of the nineteenth century, consisting of the gown, turban and shoes. Moreover, the way of using 3D models and information technologies to popularise cultural heritage in the space of digital resources is also discussed.

scholarly journals Reconstruction of the Sculpture Surface in the Process of Optical 3D Scanning

2020 ◽  
Vol 19 ◽  
Keyword(s):  
3D Models ◽  
3D Scanning ◽  
Distance Method ◽  
Scanning Process ◽  
3D Surface ◽  
Scan Data ◽  
Object Material ◽  
Technical Solutions ◽  
Inverse Distance

Currently, 3D scanning technology is used for high-precision measurements and fixing the geometric shape of various objects. However, when creating a computer 3D-model as a result of processing the array of data obtained from the scanning process, may contain errors. Errors may related to the features of the studied object (material, weight, size, location), functional properties of the software used or they may be the low qualification of the software engineer involved in processing 3D scan data. The task of this work was a finding the technical solutions, which allows one to reconstruct the objects surface, recorded using 3D scanning in the process of creating their computer 3D models. We proposed to use the inverse distance method, which is used in biometry to improve the quality of reconstruction of the 3D surface of a human face. Experiments have shown that the result of the reconstruction makes it possible to increase the accuracy of creating 3D models by recovering gaps in the surface of an object that were made during the 3D scanning process. The proposed approach allows one to construct a 3D surface without solving the triangulation problem, which leads to a reduction in computational costs.

scholarly journals All Our Eggs In One Basket: Challenges of High Resolution X-Ray Micro-Computed Tomography of Great Auk Pinguinus impennis Eggshell

2018 ◽  
Vol 2 ◽  
pp. e25794
Author(s):  
Douglas Russell ◽  
Arianna Bernucci ◽  
Amy Scott-Murray ◽  
Duncan Jackson ◽  
Farah Ahmed ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Structured Light ◽  
3D Models ◽  
Breeding Ecology ◽  
Micro Computed Tomography ◽  
History Museum ◽  
X Ray ◽  
X Ray Imaging ◽  
Scan Data

High resolution X-ray micro-computed tomography gives the ability to research objects in unprecedented detail in 3D without damaging them but applying these new techniques to specimens can be complex. In 2017 the Natural History Museum (NHM), London embarked on a ground-breaking project with University of Sheffield to compare extinct Great Auk Pinguinus impennis eggshell microstructure to that of their extant relatives to gain new insight into their breeding ecology. NHM has a ZEISS Xradia 520 Versa X-ray microscope capable of submicron X-ray imaging in 3D but using it required supporting and moving complete eggshells within the confined, potentially harsh, mechanised environment of the microscope without risk. Ensuring the correct position and orientation of each egg to image nine distinct areas on the eggshell was also a challenge. Collaboration with colleagues in the NHM Conservation and Imaging & Analysis Centres developed a bespoke solution to hold and protect the eggs during scanning. All six NHM Great Auk eggshells and the inside of the microscope were surface scanned using a handheld structured light scanner. Scan data produced 3D models from which accurate 3D printed plastic replicas were made of the three Great Auk eggs prioritised for research. Each replica was used to mould a two-part, custom-built, case for each egg constructed from conservation grade epoxy putty and lined with polyethylene foam. This provided close-fitting, durable cases which could be used for the 6-month duration of the project. Each case enclosed its matching Great Auk egg entirely and had the advantage of being rock-hard, electrically insulating and water, heat and chemical resistant. A system of three, interchangeable, tailor-made mounting brackets were designed that married with the cases and held them safely and precisely inside the microscope at the correct angles and positions for imaging. The structured light scan of the inside of the microscope was used to model the necessary rotational movements of the cases and brackets inside the scanner, ensuring that all movements had sufficient clearance to avoid risk of impact. This system successfully protected the fragile c. 200 year old eggs throughout 70 scanning sessions. This provides a methodology for high resolution X-ray micro-computed tomography imaging of any similarly sized, fragile, object.

scholarly journals Combining quantitative analysis with an elliptic Fourier descriptor: A study of pottery from the Gansu-Zhanqi site based on 3D scanning and computer technology

2020 ◽  
Author(s):  
JIN WANG ◽  
wei Qian ◽  
guoke Chen
Keyword(s):  
Quantitative Analysis ◽  
Computer Technology ◽  
Three Dimensional ◽  
3D Models ◽  
3D Scanning ◽  
Computer Assisted ◽  
Fourier Descriptor ◽  
Objective Classification ◽  
Archaeological Analysis

Abstract Pottery is an important material in archaeological studies, and the accurate classification of pottery shapes largely depends on the experience and knowledge of archaeologists. In this thesis, pottery taken from the Gansu-Zhanqi site is used for sampling. Three-dimensional (3D) models of the pottery were obtained using 3D scanning, and a computer-assisted pottery typology was studied through quantitative analysis and elliptic Fourier descriptor. This method, which can enhance and supplement the traditional methods of classifying pottery in archaeology and thereby enrich the parameters and breadth of pottery analysis, represents a new means for exploring and experimenting with objective classification and provides a new tool for traditional archaeological analysis methods.

scholarly journals THREE-DIMENSIONAL MODEL PRINTING IN ORAL AND MAXILLOFACIAL RECONSTRUCTIVE SURGERY: COMPARISON OF THREE-DIMENSIONAL MODELS AND MULTISLICE COMPUTED TOMOGRAPHY SCANS

2018 ◽  
Vol 9 ◽  
pp. 74
Author(s):  
Adhitya Latief ◽  
Pradono Suhardi ◽  
Cholid Badri
Keyword(s):  
Computed Tomography ◽  
Multislice Computed Tomography ◽  
Three Dimensional ◽  
3D Models ◽  
Three Dimensional Model ◽  
Surgical Guidance ◽  
Accuracy And Precision ◽  
Computed Tomography Scans ◽  
Scan Data ◽  
Three Dimensional Models

Objective: The objective of this study is to compare fabrication of commonly used three-dimensional (3D) models with original multislice computed tomography (MSCT) scan data for accuracy and precision in reconstruction surgery.Methods: MSCT data from 10 samples are processed and manufactured to be 3D models. Both groups are then measured and analyzed for the purpose of comparison.Results: The average mandibular measurement difference between 3D models and MSCT scans is 0.26 mm more <2%. The final results of the comparison reveal high accuracy in 3D models compared to MSCT scan data.Conclusion: The 3D model could be considered as surgical guidance for maxillofacial reconstruction surgery since it yields highly accurate results.

scholarly journals Problems of Creation and Usage of 3D Model of Structures and Theirs Possible Solution

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 181 ◽  
Author(s):  
Dalibor Bartonek ◽  
Michal Buday
Keyword(s):  
Computer Aided Design ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Cad System ◽  
Building Models ◽  
Special Cad ◽  
Aided Design ◽  
The Church

This article describes problems that occur when creating three-dimensional (3D) building models. The first problem is geometric accuracy; the next is the quality of visualization of the resulting model. The main cause of this situation is that current Computer-Aided Design (CAD) software does not have sufficient means to precision mapping the measured data of a given object in field. Therefore the process of 3D model creation is mainly a relatively high proportion of manual work when connecting individual points, approximating curves and surfaces, or laying textures on surfaces. In some cases, it is necessary to generalize the model in the CAD system, which degrades the accuracy and quality of field data. The article analyzes these problems and then recommends several variants for their solution. There are described two basic methods: using topological codes in the list of coordinates points and creating new special CAD features while using Python scripts. These problems are demonstrated on examples of 3D models in practice. These are mainly historical buildings in different locations and different designs (brick or wooden structures). These are four sacral buildings in the Czech Republic (CR): the church of saints Johns of Brno-Bystrc, the Church of St. Paraskiva in Blansko, further the Strejc’s Church in Židlochovice, and Church of St. Peter in Alcantara in Karviná city. All of the buildings were geodetically surveyed by terrestrial method while using total station. The 3D model was created in both cases in the program AUTOCAD v. 18 and MicroStation.

Effect of temperature on calibration quality of structured-light three-dimensional scanners

2014 ◽  
Vol 53 (23) ◽  
pp. 5154 ◽  
Author(s):  
M. Adamczyk ◽  
M. Kamiński ◽  
R. Sitnik ◽  
A. Bogdan ◽  
M. Karaszewski
Keyword(s):  
Structured Light ◽  
Three Dimensional ◽  
Effect Of Temperature

scholarly journals Geomatics Techniques for Submerged Heritage: a Mobile App for Tourism

2020 ◽  
Vol 16 ◽  
Keyword(s):  
New Technology ◽  
Three Dimensional ◽  
3D Models ◽  
Mobile App ◽  
Human Errors ◽  
Tourism Sector ◽  
Ancient City ◽  
Three Dimensional Models

The tourism sector is one of the major industries in Italy that has a high impact on local communities in terms of employment and economy. To show the results of a research project highlighting the use of new technology in the tourism sector, the Geomatics Laboratory of the Mediterranea University of Reggio Calabria has developed a mobile application for tourism. The case study is "Calarcheo Park", a nonaccessible underwater archaeological park located in Reggio Calabria, near the remains of the old walls of the ancient city of Reggio Calabria (Reghion, dating back to about the VIII B.C.). The main aim of this paper is to describe the process to relive and re-propose the experience of a real immersion through a journey in virtual reality. Particular attention was given to the research part concerning the simplification processes of the models inserted within an app for tourism sector. The concept app includes scenarios (seabed) and objects (Castle and artefact) obtained from three-dimensional models realized through photogrammetric techniques, therefore "heavy" models in terms of space necessary to store them, recall them and possibly process them. Considering the visualization purpose, and the metric precision needed, the 3d models were reconstructed using a rapid method. To minimize the difficulties during the direct underwater survey carried out by a human operator (e.g. limited time available during the survey, accentuated inaccuracy due to human errors), the operations were carried out using an experimental ROV (Remote Operated Vehicles), widely used to explore underwater environments, equipped with cameras to perform photogrammetric acquisition in a single dive. To enhance the results and quality of the 3d model, a procedure to improve the image quality, and optimizing the processing is also described. This work therefore illustrates the possibilities of using 3D models created by geomatics techniques within virtual environments for apps for tourism purposes

scholarly journals CHALLENGES IN FLYING QUADROTOR UNMANNED AERIAL VEHICLE FOR 3D INDOOR RECONSTRUCTION

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 423-430 ◽  
Author(s):  
J. Yan ◽  
N. Grasso ◽  
S. Zlatanova ◽  
R. C. Braggaar ◽  
D. B. Marx
Keyword(s):  
Three Dimensional ◽  
Point Clouds ◽  
3D Models ◽  
Emergency Evacuation ◽  
Vital Role ◽  
Indoor Environments ◽  
3D Tracking ◽  
High Dependency ◽  
Indoor Reconstruction

Three-dimensional modelling plays a vital role in indoor 3D tracking, navigation, guidance and emergency evacuation. Reconstruction of indoor 3D models is still problematic, in part, because indoor spaces provide challenges less-documented than their outdoor counterparts. Challenges include obstacles curtailing image and point cloud capture, restricted accessibility and a wide array of indoor objects, each with unique semantics. Reconstruction of indoor environments can be achieved through a photogrammetric approach, e.g. by using image frames, aligned using recurring corresponding image points (CIP) to build coloured point clouds. Our experiments were conducted by flying a QUAV in three indoor environments and later reconstructing 3D models which were analysed under different conditions. Point clouds and meshes were created using Agisoft PhotoScan Professional. We concentrated on flight paths from two vantage points: 1) safety and security while flying indoors and 2) data collection needed for reconstruction of 3D models. We surmised that the main challenges in providing safe flight paths are related to the physical configuration of indoor environments, privacy issues, the presence of people and light conditions. We observed that the quality of recorded video used for 3D reconstruction has a high dependency on surface materials, wall textures and object types being reconstructed. Our results show that 3D indoor reconstruction predicated on video capture using a QUAV is indeed feasible, but close attention should be paid to flight paths and conditions ultimately influencing the quality of 3D models. Moreover, it should be decided in advance which objects need to be reconstructed, e.g. bare rooms or detailed furniture.

scholarly journals THE CONCEPTUAL PRINCIPLES OF USING DIGITAL 3D MODEL AS A MEANS OF COGNITION AND REPRESENTATION OF SIGNS OF CRIMINAL OFFENSE

2021 ◽  
pp. 537-550
Author(s):  
А. Kovalenko
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
3D Scanning ◽  
Criminal Proceedings ◽  
Three Dimensional Model ◽  
Significant Information ◽  
Criminal Offense ◽  
Spatial Features ◽  
Object Based

The article forms the conceptual principles of use of digital 3D model as means of cognition and display of signs of a criminal offense in criminal proceedings. A 3D model can be defined as a digital, three-dimensional image of an object, which reflects its external structure and color, accurately and proportionally reproduces the ratio of its spatial features. It can directly contain information about the shape, proportions, color and mutual placement in space of the elements of the original object. Provided the manufacturing technology is followed, the model is isomorphic to original object. Such a model serves as a means of cognition and reflection of forensically significant features of a criminal offense. The main methods for making 3D models are reconstruction (modeling) and scanning. 3D reconstruction (or 3D modeling) can be defined as the process of reproducing a 3D model of a forensic significant object based on information about it contained in the materials of criminal proceedings. The reconstructed models can be used during investigative (search) actions and for solving organizational problems. 3D scanning consists in the direct fixation of the external spatial features of the object using a special software and hardware complex, followed by the formation of a digital three-dimensional model of the object. Subject to compliance with the procedural requirements for the use of technical means of fixing forensically significant information, scanned 3D models will be sources of evidentiary information in criminal proceedings. 3D scanning is a promising method for recording the course and results of an inspection of the scene of an incident, inspection of a corpse or things; it can be used for fixing signs of a person's appearance, as well as for solving identification and diagnostics tasks in forensic activities. The invariability of the 3D model can be ensured by calculating the hash of the file that contains it.

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