scholarly journals Image-based metric heritage modeling in the near-infrared spectrum

2020 ◽  
Author(s):  
Efstathios Adamopoulos ◽  
Alessandro Bovero ◽  
Fulvio Rinaudo
Keyword(s):  
Near Infrared ◽  
Three Dimensional ◽  
Visible Spectrum ◽  
Lighting Conditions ◽  
Image Based Modeling ◽  
Spectral Models ◽  
Software Implementations ◽  
Automatic Software ◽  
Accuracy Of Results

Abstract Digital photogrammetry and spectral imaging are widely used in heritage sciences, towards the comprehensive recording, understanding, and protection of historical artefacts and artworks. The availability of consumer-grade modified cameras for spectral acquisition, as an alternative to expensive multispectral sensors and multi-sensor apparatuses, along with semi-automatic software implementations of Structure-from-Motion (SfM) and Multiple-View-Stereo (MVS) algorithms, has made more feasible than ever the combination of those techniques. In the research presented here, the authors assess image-based modeling from near-infrared (NIR) imagery acquired with modified sensors, with applications on tangible heritage. Three-dimensional meshes, textured with the non-visible data, are produced and evaluated. Specifically, metric evaluations are conducted through extensive comparisons with models produced with high-resolution visible (VIS) spectrum image-based modeling, to check accuracy of results. Furthermore, the authors observe and discuss, when the implemented NIR modeling approach, enhances the preservation of surface detail on the reconstructed spectral models or counteracts certain problems arising from lighting conditions during VIS acquisition. Radiometric properties of the produced results are evaluated on the capacity to enhance observation towards the characterization of surface and under-surface state of preservation, and consequently, to support conservation interventions, in comparison to the respective results in visible spectrum.

scholarly journals Assessing the Stability of Surface Lights for use in Retrievals of Nocturnal Atmospheric Parameters

2019 ◽  
Author(s):  
Jeremy E. Solbrig ◽  
Steven D. Miller ◽  
Jianglong Zhang ◽  
Lewis Grasso ◽  
Anton Kliewer
Keyword(s):  
Near Infrared ◽  
Correlation Coefficients ◽  
Visible Spectrum ◽  
Light Sources ◽  
Infrared Observations ◽  
Spatially Resolved ◽  
Relative Standard ◽  
Geometric Variables ◽  
The Stability

Abstract. Detection and characterization of aerosols is inherently limited at night due to a lack of sensitivity—information typically provided by visible spectrum observations. The VIIRS Day/Night Band (DNB) onboard the Suomi-NPP satellite is a first-of-its-kind calibrated sensor capable of collecting visible/near-infrared observations during both day and night. Multiple studies have suggested that anthropogenic light emissions such as those from cities and gas flares may be useable as light sources for retrieval of atmospheric properties including cloud and aerosol optical depth. However, their use in this capacity requires proper characterization of their intrinsic variation, which represents a source of retrieval uncertainty. In this study we use 18 months of cloud-cleared VIIRS data collected over five selected geographic domains to assess the stability of anthropogenic light emissions and their response to varied satellite and lunar geometries. Timeseries are developed for each location in each domain for DNB radiance, four infrared channels, and satellite and lunar geometric variables, and spatially-resolved correlation coefficients are computed between DNB radiance and each of the other variables. This analysis finds that while many emissive light sources are too unstable to be used reliably for atmospheric retrievals, some sources exhibit a sufficient stability (relative standard deviation

Fabrication and characterization of three-dimensional all metallic photonic crystals for near infrared applications

2009 ◽  
Vol 94 (4) ◽  
pp. 041122 ◽  
Author(s):  
Yu-Lin Yang ◽  
Fu-Ju Hou ◽  
Shich-Chuan Wu ◽  
Wen-Hsien Huang ◽  
Ming-Chih Lai ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Near Infrared ◽  
Three Dimensional ◽  
Metallic Photonic Crystals ◽  
Fabrication And Characterization

scholarly journals Beyond the visible spectrum – applying 3D multispectral full-body imaging to the VirtoScan system

2021 ◽  
Author(s):  
Sören Kottner ◽  
Martin M. Schulz ◽  
Florian Berger ◽  
Michael Thali ◽  
Dominic Gascho
Keyword(s):  
Near Infrared ◽  
Three Dimensional ◽  
Visible Spectrum ◽  
Image Data ◽  
3D Models ◽  
Light Sources ◽  
Ct Scanner ◽  
Body Imaging ◽  
Wide Range ◽  
Full Body

AbstractMultispectral photography offers a wide range of applications for forensic investigations. It is commonly used to detect latent evidence and to enhance the visibility of findings. Additionally, three-dimensional (3D) full-body documentation has become much easier and more affordable in recent years. However, the benefits of performing 3D imaging beyond the visible (VIS) spectrum are not well known, and the technique has not been widely used in forensic medical investigations. A multicamera setup was used to employ multispectral photogrammetry between 365 and 960 nm in postmortem investigations. The multicamera setup included four modified digital cameras, ultraviolet (UV) and near-infrared (NIR) light sources and supplemental lens filters. Full-body documentation was performed in conjunction with the use of a medical X-ray computed tomography (CT) scanner to automate the imaging procedure. Textured 3D models based on multispectral datasets from four example cases were reconstructed successfully. The level of detail and overall quality of the 3D reconstructions varied depending on the spectral range of the image data. Generally, the NIR datasets showed enhanced visibility of vein patterns and specific injuries, whereas the UV-induced datasets highlighted foreign substances on the skin. Three-dimensional multispectral full-body imaging enables the detection of latent evidence that is invisible to the naked eye and allows visualization, documentation and analysis of evidence beyond the VIS spectrum.

scholarly journals Assessing the stability of surface lights for use in retrievals of nocturnal atmospheric parameters

2020 ◽  
Vol 13 (1) ◽  
pp. 165-190 ◽  
Author(s):  
Jeremy E. Solbrig ◽  
Steven D. Miller ◽  
Jianglong Zhang ◽  
Lewis Grasso ◽  
Anton Kliewer
Keyword(s):  
Near Infrared ◽  
Correlation Coefficients ◽  
Visible Spectrum ◽  
Light Sources ◽  
Strongly Correlated ◽  
Spatially Resolved ◽  
Relative Standard ◽  
Geometric Variables ◽  
The Stability

Abstract. The detection and characterization of aerosols are inherently limited at night because the important information provided by visible spectrum observations is not available and infrared bands have limited sensitivity to aerosols. The VIIRS Day–Night Band (DNB) onboard the Suomi-NPP satellite is a first-of-its-kind calibrated sensor capable of collecting visible and near-infrared observations during both day and night. Multiple studies have suggested that anthropogenic light emissions such as those from cities and gas flares may be useable as light sources for the retrieval of atmospheric properties, including cloud and aerosol optical depth. However, their use in this capacity requires proper characterization of their intrinsic variation, which represents a source of retrieval uncertainty. In this study we use 18 months of cloud-cleared VIIRS data collected over five selected geographic domains to assess the stability of anthropogenic light emissions and their response to varied satellite and lunar geometries. Time series are developed for each location in each domain for DNB radiance, four infrared channels, and satellite and lunar geometric variables, and spatially resolved correlation coefficients are computed between DNB radiance and each of the other variables. This analysis finds that while many emissive light sources are too unstable to be used reliably for atmospheric retrievals, some sources exhibit a sufficient stability (relative standard deviation <20 %). Additionally, we find that while the radiance variability of surrounding surfaces (i.e., unpopulated land and ocean) is largely dependent on lunar geometry, the anthropogenic light sources are more strongly correlated with satellite viewing geometry. Understanding the spatially resolved relationships between DNB radiance and other parameters is a necessary first step towards characterizing anthropogenic light emissions and establishes a framework for a model to describe variability in a more general sense.

scholarly journals Photoacoustic in vivo 3D imaging of tumor using a highly tumor-targeting probe under high-threshold conditions

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hisatsugu Yamada ◽  
Natsuki Matsumoto ◽  
Takanori Komaki ◽  
Hiroaki Konishi ◽  
Yu Kimura ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Tumor Targeting ◽  
3D Imaging ◽  
Near Infrared ◽  
Three Dimensional ◽  
Cyanine Dye ◽  
High Threshold ◽  
Threshold Conditions

Abstract Three-dimensional (3D) representation of a tumor with respect to its size, shape, location, and boundaries is still a challenge in photoacoustic (PA) imaging using artificial contrast agents as probes. We carried out PA imaging of tumors in mice using 800RS-PMPC, which was obtained by coupling of 800RS, a near-infrared cyanine dye, with PMPC, a highly selective tumor-targeting methacrylate polymer having phosphorylcholine side chains, as a probe. The conjugate 800RS-PMPC forms compact nanoparticles (dDLS = 14.3 nm), retains the biocompatibility of the parent polymer (PMPC) and exhibits unprecedented PA performance. When applied to mice bearing a 6 × 3 × 3 mm3 tumor buried 6 mm beneath the skin, the probe 800RS-PMPC selectively accumulates in the tumor and emits PA signals that are strong enough to be unambiguously distinguished from noise signals of endogenous blood/hemoglobin. The PA image thus obtained under high-threshold conditions allows 3D characterization of the tumor in terms of its size, shape, location, and boundaries.

scholarly journals Characterization and Evaluation of the Efficiency of TiO2/Zinc Phthalocyanine Nanocomposites as Photocatalysts for Wastewater Treatment Using Solar Irradiation

2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
Antonio E. H. Machado ◽  
Marcela D. França ◽  
Valdemir Velani ◽  
Gabriel A. Magnino ◽  
Hosana M. M. Velani ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Visible Spectrum ◽  
Zinc Phthalocyanine ◽  
Solar Irradiation ◽  
Absorption Bands ◽  
Intense Absorption ◽  
Spectrum Region

This work reports the characterization of composites prepared by the association between zinc phthalocyanine (ZnPc) and titanium dioxide. These composites are better photocatalysts for wastewater decontamination mediated by solar radiation than pureTiO2, performance that remains even when reused. The UV-Vis diffuse reflectance absorption spectra show for these composites two intense absorption bands. The first covers the ultraviolet and part of the visible spectrum region until 460 nm (2.7 eV), whereas the second, nonstructured, goes from 475 nm until the near infrared with an absorption peak at 683 nm attributed to the Q band of ZnPc. The production of additionale−/h+pairs by these aggregates when photoexcited, their capability to act as charge carrier, the thickness and regularity of their distribution on theTiO2surface seem to be important parameters for the performance observed for these composites.

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

convergent-beam diffraction from surfaces

1987 ◽  
Vol 45 ◽  
pp. 30-33
Author(s):  
J. A. Eades ◽  
A. E. Smith ◽  
D. F. Lynch
Keyword(s):  
Reciprocal Lattice ◽  
Three Dimensional ◽  
Grazing Incidence ◽  
Three Dimensions ◽  
Plane Figure ◽  
Transmission Electron ◽  
Convergent Beam ◽  
Beam Patterns ◽  
Beam Diffraction

It is quite simple (in the transmission electron microscope) to obtain convergent-beam patterns from the surface of a bulk crystal. The beam is focussed onto the surface at near grazing incidence (figure 1) and if the surface is flat the appropriate pattern is obtained in the diffraction plane (figure 2). Such patterns are potentially valuable for the characterization of surfaces just as normal convergent-beam patterns are valuable for the characterization of crystals.There are, however, several important ways in which reflection diffraction from surfaces differs from the more familiar electron diffraction in transmission.GeometryIn reflection diffraction, because of the surface, it is not possible to describe the specimen as periodic in three dimensions, nor is it possible to associate diffraction with a conventional three-dimensional reciprocal lattice.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

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