Validation of a three-dimensional facial scanning system based on structured light techniques

3D (three-dimensional) structured light scanning system is widely used in the field of reverse engineering, quality inspection, and so forth. Camera calibration is the key for scanning precision. Currently, 2D (two-dimensional) or 3D fine processed calibration reference object is usually applied for high calibration precision, which is difficult to operate and the cost is high. In this paper, a novel calibration method is proposed with a scale bar and some artificial coded targets placed randomly in the measuring volume. The principle of the proposed method is based on hierarchical self-calibration and bundle adjustment. We get initial intrinsic parameters from images. Initial extrinsic parameters in projective space are estimated with the method of factorization and then upgraded to Euclidean space with orthogonality of rotation matrix and rank 3 of the absolute quadric as constraint. Last, all camera parameters are refined through bundle adjustment. Real experiments show that the proposed method is robust, and has the same precision level as the result using delicate artificial reference object, but the hardware cost is very low compared with the current calibration method used in 3D structured light scanning system.

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Three-dimensional facial anthropometry of unilateral cleft lip infants with a structured light scanning system

Journal of Plastic Reconstructive & Aesthetic Surgery ◽

10.1016/j.bjps.2013.04.007 ◽

2013 ◽

Vol 66 (8) ◽

pp. 1109-1116 ◽

Cited By ~ 18

Author(s):

Guanghui Li ◽

Jianhua Wei ◽

Xi Wang ◽

Guofeng Wu ◽

Dandan Ma ◽

...

Keyword(s):

Cleft Lip ◽

Structured Light ◽

Three Dimensional ◽

Scanning System ◽

Structured Light Scanning ◽

Facial Anthropometry

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Three-Dimensional Scanning System with Double Structured-Light Sensors

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.226-228.1938 ◽

2012 ◽

Vol 226-228 ◽

pp. 1938-1941

Author(s):

Bin Peng ◽

Hai Shu Tan ◽

Fu Qiang Zhou

Keyword(s):

Structured Light ◽

Three Dimensional ◽

Measurement Range ◽

Scanning System ◽

3D Vision ◽

3D Surface ◽

Surface Data ◽

Planar Target ◽

The Mathematical Model ◽

Measurement Area

Three-dimensional (3D) vision scanning measurement is widely used in industry for its ability to obtain the 3D surface data of the object. Aiming at overcoming the shortcomings of 3D scanning measurement system with single structured-light sensor, such as limited measurement range and blind measurement area, a scanning system based on double structured-light sensors (DSS) is established. The object is scanned from two different directions, and the 3D surface coordinates are unified to the measurement coordinate system to obtain the 3D surface of the measured object. In this paper, the mathematical model of the DSS scanning system is established. Meanwhile, an on-site calibration approach based on planar target is proposed to complete the system calibration task. Finally, experimental results of practical data are given to show the feasibility and validity of the proposed system.

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Three-dimensional periorbital asymmetry assessment of congenital microphthalmia children with a structured light 3D scanning system

Journal of Cranio-Maxillofacial Surgery ◽

10.1016/j.jcms.2020.12.016 ◽

2021 ◽

Author(s):

Bowei Yuan ◽

Xue Jiang ◽

Yan Liu ◽

Jie Dong ◽

Dongmei Li

Keyword(s):

Structured Light ◽

Three Dimensional ◽

3D Scanning ◽

Scanning System

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Three-Dimensional Reproducibility of the Soft Tissue Landmarks Taken by Structured-Light Facial Scanner in Accordance with the Head Position Change

Healthcare ◽

10.3390/healthcare9040428 ◽

2021 ◽

Vol 9 (4) ◽

pp. 428

Author(s):

Seung-Hoon Oh ◽

Jung-Soo Park ◽

Jae-Jun Ryu ◽

In-Seok Song ◽

Seok-Ki Jung

Keyword(s):

Soft Tissue ◽

Horizontal Plane ◽

Structured Light ◽

Three Dimensional ◽

Orbital Plane ◽

Head Position ◽

Position Change ◽

3D Images ◽

Structured Light Scanner ◽

Facial Scanning

The aim of this study was to evaluate the three-dimensional reproducibility of the structured-light facial scanner according to the head position change. A mannequin head was used and angle of the mannequin’s axis-orbital plane to the true horizontal plane was adjusted to +10, +5, 0, −5, and −10°. Facial scanning was conducted 30 times, respectively, and 150 3D images were obtained. Reoriented landmarks of each group were compared and analyzed. Reproducibility decreased as the distance from the facial center increased. Additionally, the landmarks below showed lower reproducibility and higher dispersion than landmarks above. These differences occurred mainly in the anteroposterior direction as opposed to other directions. Positive inclination of the head position showed superior reproducibility compared to a negative inclination. This study showed that reproducibility of a structured-light scanner could be varied depending on the head position. Inaccuracies of landmarks in the anteroposterior direction are greater than in other directions. This means that evaluations of the profile using a structured-light scanner should be made carefully. Therefore, the proper head position should be set to ensure the accuracy of the image.

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A High-Precision Registration Technology Based on Bundle Adjustment in Structured Light Scanning System

Mathematical Problems in Engineering ◽

10.1155/2014/897347 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Jianying Yuan ◽

Qiong Wang ◽

Xiaoliang Jiang ◽

Bailin Li

Keyword(s):

High Precision ◽

Large Scale ◽

Structured Light ◽

Bundle Adjustment ◽

Scanning System ◽

Control Points ◽

Registration Method ◽

Global Control ◽

3D Data ◽

Structured Light Scanning

The multiview 3D data registration precision will decrease with the increasing number of registrations when measuring a large scale object using structured light scanning. In this paper, we propose a high-precision registration method based on multiple view geometry theory in order to solve this problem. First, a multiview network is constructed during the scanning process. The bundle adjustment method from digital close range photogrammetry is used to optimize the multiview network to obtain high-precision global control points. After that, the 3D data under each local coordinate of each scan are registered with the global control points. The method overcomes the error accumulation in the traditional registration process and reduces the time consumption of the following 3D data global optimization. The multiview 3D scan registration precision and efficiency are increased. Experiments verify the effectiveness of the proposed algorithm.

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

Heritage Science ◽

10.1186/s40494-021-00544-x ◽

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.

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

Applied Sciences ◽

10.3390/app11010301 ◽

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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