scholarly journals A comparison between stereophotogrammetry and smartphone structured light technology for three-dimensional face scanning

2022 ◽  
Author(s):  
Giorgio D‘Ettorre ◽  
Marco Farronato ◽  
Ettore Candida ◽  
Vincenzo Quinzi ◽  
Cristina Grippaudo
Keyword(s):  
San Francisco ◽  
Image Acquisition ◽  
Structured Light ◽  
Three Dimensional ◽  
Acquisition Time ◽  
Smartphone Applications ◽  
Processing Times ◽  
Deviation Analysis ◽  
Reference Images ◽  
Surface Deviation

ABSTRACT Objectives To compare three-dimensional facial scans obtained by stereophotogrammetry with two different applications for smartphone supporting the TrueDepth system, a structured light technology. Materials and Methods Facial scans of 40 different subjects were acquired with three different systems. The 3dMDtrio Stereophotogrammetry System (3dMD, Atlanta, Ga) was compared with a smartphone (iPhone Xs; Apple, Cupertino, Calif) equipped with the Bellus3D Face Application (version 1.6.11; Bellus3D Inc, Campbell, Calif) or Capture (version 1.2.5; Standard Cyborg Inc, San Francisco, Calif). Times of image acquisition and elaboration were recorded. The surface-to-surface deviation and the distance between 18 landmarks from 3dMD reference images to those acquired with Bellus3D or Capture were measured. Results Capturing and processing times with the smartphone applications were considerably longer than with the 3dMD system. The surface-to-surface deviation analysis between the Bellus3D and 3dMD showed an overlap percentage of 80.01% ± 5.92% and 56.62% ± 7.65% within the ranges of 1 mm and 0.5 mm discrepancy, respectively. Images from Capture showed an overlap percentage of 81.40% ± 9.59% and 56.45% ± 11.62% within the ranges of 1 mm and 0.5 mm, respectively. Conclusions The face image acquisition with the 3dMD device is fast and accurate, but bulky and expensive. The new smartphone applications combined with the TrueDepth sensors show promising results. They need more accuracy from the operator and more compliance from the patient because of the increased acquisition time. Their greatest advantages are related to cost and portability.

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 EVALUATING MOBILE LASER SCANNING FOR LANDSLIDE MONITORING

2018 ◽  
Vol XLII-3/W4 ◽  
pp. 211-219
Author(s):  
N. A. Fuad ◽  
A. R. Yusoff ◽  
M. P. M. Zam ◽  
A. Aspuri ◽  
M. F. Salleh ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Human Life ◽  
Three Dimensional ◽  
Landslide Monitoring ◽  
Landslide Area ◽  
Project Area ◽  
Deviation Analysis ◽  
Gps Survey ◽  
Surface Deviation ◽  
Dimensional Surface

<p><strong>Abstract.</strong> Landslide is one of the natural disasters that give a huge impact to human life and social-economic development. Landslide needs to be monitored periodically in order to avoid loss of human life and damages of properties. Various methods have been used for monitoring landslide. This aim of the research is to evaluate the potential of mobile laser scanning technique for monitoring of landslide area. The objectives of the research are to acquire three-dimensional surface data of landslide area in different epochs and to analyze the movement of the landslide area using three-dimensional surface deviation and ground surveying techniques. The methodology begins with the GPS survey for the establishment of ground control points for the project area. The total station survey was then carried out to measure the three-dimensional coordinates of twenty well distributed targets located at the project area. The data collection phase was then continuing with the mobile laser scanning survey. The processing of the two epochs data acquired from both techniques was then carried out simultaneously and the methodology concluded with the output comparison analysis for the movement detection of the land slip. The finding shows that the mobile laser scanning provides fast and accurate data acquisition technique of the landslide surface. The surface deviation analysis of the two epochs laser scanning data was capable to detect the movement occurred in the project area. The results were successfully evaluated using the changes of the three-dimensional coordinates of the targets from the two epoch’s ground surveying data.</p>

Evaluation of mandibular symmetry and morphology in adult patients with unilateral posterior crossbite: a CBCT study using a surface-to-surface matching technique

2020 ◽  
Vol 42 (6) ◽  
pp. 650-657 ◽  
Author(s):  
Rosalia Leonardi ◽  
Simone Muraglie ◽  
Antonino Lo Giudice ◽  
K S Aboulazm ◽  
R Nucera
Keyword(s):  
Three Dimensional ◽  
Adult Patients ◽  
Surface Matching ◽  
Control Group ◽  
Gonial Angle ◽  
Engineering Software ◽  
Mandibular Asymmetry ◽  
Deviation Analysis ◽  
Matching Technique ◽  
Surface Deviation

Summary Objectives To investigate mandibular morphology in adults affected by posterior unilateral crossbite (PUXB) and to evaluate the hemi mandibular volumes from the crossbite (CB) and non-CB sides of the same patients. Methods Thirty-eight cone beam computed tomography (CBCT) images were consecutively recruited and the Digital Imaging and Communications in Medicine (DICOM)-formatted scans were volume rendered into a surface three-dimensional (3D) mesh model and volumes to obtain the 3D model of the mandibular bone. To achieve the surface point-to-point analysis of the mandibular models, a reverse engineering software was used. The same procedure was performed for an age-matched control group (19 CBCT images). Results Total mandibular volume showed a difference of 2.46 cm3 between patients and controls, which was not statistically significant. A mean difference of 1.53 cm3 was found comparing the hemi mandibular volumes from the CB and non-CB sides of PUXB patients, this difference was statistically significant (P ≤ 0.01). Findings for the surface-to-surface deviation analysis, demonstrated a higher percentage of mismatch in patients PUXB, over 10% at 0.5 mm tolerance level. Limitations Limitations are related to the intrinsic surfaces matching methodology, that make difficult to evaluate discrepancies among different mandibular anatomical units. Conclusion Adult patients affected by PUXB show a greater mandibular structural asymmetry compared to controls because of a lower matching percentage obtained from the surface-to-surface matching technique. Implications Treatment of adult patients affected by PUXB should take into consideration the possibility of a mild mandibular asymmetry mainly localized at the condyle and gonial angle levels.

SEISMIC VULNERABILITY ASSESSMENT FOR SAN FRANCISCO TEMPLE IN MORELIA, MEXICO

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 207-2016
Author(s):  
Guillermo Martinez ◽  
David Castillo ◽  
José Jara ◽  
Bertha Olmos
Keyword(s):  
San Francisco ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Middle Part ◽  
Seismic Demands ◽  
Modeling And Analysis ◽  
Seismic Records ◽  
Cracking Pattern ◽  
The Temple

This paper presents a first approximation of the seismic vulnerability of a sixteenth century building which is part of the historical center of Morelia, Mexico. The city was declared World Heritage by United Nations Educational, Scientific and Cultural Organization in 1991. The modeling and analysis of the building was carried out using a three-dimensional elastic tetrahedral finite elements model which was subjected to probabilistic seismic demands with recurrences of 500 yrs and 1000 yrs in addition to real seismic records. The model was able to correctly identify cracking pattern in different parts of the temple due to gravitational forces. High seismic vulnerability of the arched window and the walls of the middle part of the bell tower of the temple was indicated by the seismic analysis of the model.

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 Validity and reliability of smartphone applications for measurement of hip rotation, compared with three‐dimensional motion analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Phob Ganokroj ◽  
Nuchanun Sompornpanich ◽  
Pichitpol Kerdsomnuek ◽  
Bavornrat Vanadurongwan ◽  
Pisit Lertwanich
Keyword(s):  
Internal Rotation ◽  
Motion Analysis ◽  
Supine Position ◽  
External Rotation ◽  
Three Dimensional ◽  
Angle Measurement ◽  
Smartphone Applications ◽  
Rater Reliability ◽  
Link Type ◽  
Hip Rotation

Abstract Background Measurement of hip rotation is a crucial clinical parameter for the identification of hip problems and the monitoring of symptoms. The objective of this study was to determine whether the use of two smartphone applications is valid and reliable for the measurement of hip rotation. Methods An experimental, cross-sectional study was undertaken to assess passive hip internal and external rotation in three positions by two examiners. The hip rotational angles were measured by a smartphone clinometer application in the sitting and prone positions, and by a smartphone compass application in the supine position; their results were compared with those of the standard, three-dimensional, motion analysis system. The validities and inter-rater and intra-rater reliabilities of the smartphone applications were evaluated. Results The study involved 24 participants. The validities were good to excellent for the internal rotation angles in all positions (ICC 0.81–0.94), good for the external rotation angles in the prone position (ICC 0.79), and fair for the sitting and supine positions (ICC 0.70–0.73). The measurement of the hip internal rotation in the supine position had the highest ICC value of 0.94 (0.91, 0.96). The two smartphone applications showed good-to-excellent intra-rater reliability, but good-to-excellent inter-rater reliability for only three of the six positions (two other positions had fair reliability, while one position demonstrated poor reliability). Conclusions The two smartphone applications have good-to-excellent validity and intra-rater reliability, but only fair-to-good inter-rater reliability for the measurement of the hip rotational angle. The most valid hip rotational position in this study was the supine IR angle measurement, while the lowest validity was the ER angle measurement in the sitting position. The smartphone application is one of the practical measurements in hip rotational angles. Trial registration Number 20181022003 at the Thai Clinical Trials Registry (http://www.clinicaltrials.in.th) which was retrospectively registered at 2018-10-18 15:30:29.

scholarly journals Combining 3D Structured Light Imaging and Spine X-ray Data Improves Visualization of the Spinous Lines in the Scoliotic Spine

2020 ◽  
Vol 11 (1) ◽  
pp. 301
Author(s):  
Sławomir Paśko ◽  
Wojciech Glinkowski
Keyword(s):  
Radiation Exposure ◽  
Surface Topography ◽  
Structured Light ◽  
Spinous Process ◽  
Three Dimensional ◽  
Diagnostic System ◽  
Measurement Tool ◽  
Adequate Treatment ◽  
X Ray ◽  
Spinous Processes

Scoliosis is a three-dimensional trunk and spinal deformity. Patient evaluation is essential for the decision-making process and determines the selection of specific and adequate treatment. The diagnosis requires a radiological evaluation that exposes patients to radiation. This exposure reaches hazardous levels when numerous, repetitive radiographic studies are required for diagnostics, monitoring, and treatment. Technological improvements in radiographic devices have significantly reduced radiation exposure, but the risk for patients remains. Optical three-dimensional surface topography (3D ST) measurement systems that use surface topography (ST) to screen, diagnose, and monitor scoliosis are safer alternatives to radiography. The study aimed to show that the combination of plain X-ray and 3D ST scans allows for an approximate presentation of the vertebral column spinous processes line in space to determine the shape of the spine’s deformity in scoliosis patients. Twelve patients diagnosed with scoliosis, aged 13.1 ± 4.5 years (range: 9 to 20 years) (mean: Cobb angle 17.8°, SD: ±9.5°) were enrolled in the study. Patients were diagnosed using full-spine X-ray and whole torso 3D ST. The novel three-dimensional assessment of the spinous process lines by merging 3D ST and X-ray data in patients with scoliosis was implemented. The method’s expected uncertainty is less than 5 mm, which is better than the norm for a standard measurement tool. The presented accuracy level is considered adequate; the proposed solution is accurate enough to monitor the changes in the shape of scoliosis’s spinous processes line. The proposed method allows for a relatively precise calculation of the spinous process lines based on a three-dimensional point cloud obtained with a four-directional, three-dimensional structured light diagnostic system and a single X-ray image. The method may help reduce patients’ total radiation exposure and avoid one X-ray in the sagittal projection if biplanar radiograms are required for reconstructing the three-dimensional line of the spinous processes line.

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