Three-dimensional Underwater Measuring by Structured Light Projection

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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Three-dimensional surface reconstruction within noncontact diffuse optical tomography using structured light

Journal of Biomedical Optics ◽

10.1117/1.jbo.17.12.126009 ◽

2012 ◽

Vol 17 (12) ◽

pp. 126009 ◽

Cited By ~ 2

Author(s):

Kirstin Baum ◽

Raimo Hartmann ◽

Tobias Bischoff ◽

Jan O. Oelerich ◽

Stephan Finkensieper ◽

...

Keyword(s):

Surface Reconstruction ◽

Structured Light ◽

Optical Tomography ◽

Three Dimensional ◽

Diffuse Optical Tomography ◽

Dimensional Surface

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Three dimensional reconstruction of irregular industrial sheetmetal parts based on structured light

10.1117/12.655020 ◽

2005 ◽

Author(s):

Jianqing Zhang ◽

Li Zheng

Keyword(s):

Structured Light ◽

Three Dimensional ◽

Three Dimensional Reconstruction ◽

Dimensional Reconstruction

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Evolution of orbital angular momentum in three-dimensional structured light

Physical Review A ◽

10.1103/physreva.98.043846 ◽

2018 ◽

Vol 98 (4) ◽

Cited By ~ 7

Author(s):

Ahmed H. Dorrah ◽

Carmelo Rosales-Guzmán ◽

Andrew Forbes ◽

Mo Mojahedi

Keyword(s):

Angular Momentum ◽

Orbital Angular Momentum ◽

Structured Light ◽

Three Dimensional

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Quantum Structured Light: Non-classical Spin Texture of Twisted Single-photon Pulses

10.21203/rs.3.rs-507381/v1 ◽

2021 ◽

Author(s):

Li-Ping Yang ◽

Zubin Jacob

Keyword(s):

Spin Density ◽

Electromagnetic Waves ◽

Single Photon ◽

Structured Light ◽

Three Dimensional ◽

Quantum Spin ◽

Single Photons ◽

Spin Order ◽

Spin Noise ◽

Spin Texture

Abstract Classical structured light with controlled polarization and orbital angular momentum (OAM) of electromagnetic waves has varied applications in optical trapping, bio-sensing, optical communications and quantum simulations. The classical electromagnetic theory of such structured light beams and pulses have advanced significantly over the last two decades. However, a framework for the quantum density of spin and OAM for single-photons remains elusive. Here, we develop a theoretical framework and put forth the concept of quantum structured light for space-time wavepackets at the single-photon level. Our work marks a paradigm shift beyond scalar-field theory as well as the paraxial approximation and can be utilized to study the quantum properties of the spin and OAM of all classes of twisted quantum light pulses. We capture the uncertainty in full three-dimensional (3D) projections of vector spin demonstrating their quantum behavior beyond the conventional concept of classical polarization. Even in laser beams with high OAM along the propagation direction, we predict the existence of large OAM quantum fluctuations in the transverse plane which can be verified experimentally. We show that the spin density generates modulated helical texture beyond the paraxial limit and exhibits distinct statistics for Fock-state vs. coherent-state twisted pulses. We introduce the quantum correlator of photon spin density to characterize the nonlocal spin noise providing a rigorous parallel with fermionic spin noise operators. Our work paves the way for quantum spin-OAM physics in twisted single photon pulses and also opens explorations for new phases of light with long-range spin order.

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Calibration Method for Line-Structured Light Three-Dimensional Measurements Based on a Single Circular Target

Applied Sciences ◽

10.3390/app12020588 ◽

2022 ◽

Vol 12 (2) ◽

pp. 588

Author(s):

Jun Wang ◽

Xuexing Li

Keyword(s):

Structured Light ◽

Three Dimensional ◽

Calibration Method ◽

Optical Center ◽

3D Measurements ◽

Light Plane ◽

Laser Projector ◽

Dimensional Measurements ◽

Intersection Points ◽

Circular Target

Single circular targets are widely used as calibration objects during line-structured light three-dimensional (3D) measurements because they are versatile and easy to manufacture. This paper proposes a new calibration method for line-structured light 3D measurements based on a single circular target. First, the target is placed in several positions and illuminated by a light beam emitted from a laser projector. A camera captures the resulting images and extracts an elliptic fitting profile of the target and the laser stripe. Second, an elliptical cone equation defined by the elliptic fitting profile and optical center of the camera is established based on the projective geometry. By combining the obtained elliptical cone and the known diameter of the circular target, two possible positions and orientations of the circular target are determined and two groups of 3D intersection points between the light plane and the circular target are identified. Finally, the correct group of 3D intersection points is filtered and the light plane is progressively fitted. The accuracy and effectiveness of the proposed method are verified both theoretically and experimentally. The obtained results indicate that a calibration accuracy of 0.05 mm can be achieved for an 80 mm × 80 mm planar target.

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