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hyperspectral imaging

Woon Cho, Jinbeum Jang, Andreas Koschan, Mongi A Abidi, Joonki Paik
A fundamental limitation of hyperspectral imaging is the inter-band misalignment correlated with subject motion during data acquisition. One way of resolving this problem is to assess the alignment quality of hyperspectral image cubes derived from the state-of-the-art alignment methods. In this paper, we present an automatic selection framework for the optimal alignment method to improve the performance of face recognition. Specifically, we develop two qualitative prediction models based on: 1) a principal curvature map for evaluating the similarity index between sequential target bands and a reference band in the hyperspectral image cube as a full-reference metric; and 2) the cumulative probability of target colors in the HSV color space for evaluating the alignment index of a single sRGB image rendered using all of the bands of the hyperspectral image cube as a no-reference metric...
November 28, 2016: Optics Express
Kyle T Hufziger, Sergei V Bykov, Sanford A Asher
We constructed the first deep ultraviolet (UV) Raman standoff wide-field imaging spectrometer. Our novel deep UV imaging spectrometer utilizes a photonic crystal to select Raman spectral regions for detection. The photonic crystal is composed of highly charged, monodisperse 35.5 ± 2.9 nm silica nanoparticles that self-assemble in solution to produce a face centered cubic crystalline colloidal array that Bragg diffracts a narrow ∼1.0 nm full width at half-maximum (FWHM) UV spectral region. We utilize this photonic crystal to select and image two different spectral regions containing resonance Raman bands of pentaerythritol tetranitrate (PETN) and NH4NO3 (AN)...
November 28, 2016: Applied Spectroscopy
Corinne D Nawn, Brian E Souhan, Robert Carter, Caitlin Kneapler, Nicholas Fell, Jing Yong Ye
No abstract text is available yet for this article.
November 1, 2016: Journal of Biomedical Optics
J Ofner, J Kirschner, E Eitenberger, G Friedbacher, A Kasper-Giebl, H Lohninger, C Eisenmenger-Sittner, B Lendl
The quality of chemical imaging, especially multisensor hyperspectral imaging, strongly depends on sample preparation techniques and instrumental infrastructure but also on the choice of an appropriate imaging substrate. To optimize the combined imaging of Raman microspectroscopy, scanning-electron microscopy and energy-dispersive X-ray spectroscopy, a novel substrate was developed based on sputtering of highly purified aluminium onto classical microscope slides. The novel aluminium substrate overcomes several disadvantages of classical substrates like impurities of the substrate material and contamination of the surface as well as surface roughness and homogeneity...
November 28, 2016: Journal of Microscopy
Alex Soares Duarte, Christoph Schnedermann, Philipp Kukura
We present a wide-field imaging implementation of Fourier transform coherent anti-Stokes Raman scattering (wide-field detected FT-CARS) microscopy capable of acquiring high-contrast label-free but chemically specific images over the full vibrational 'fingerprint' region, suitable for a large field of view. Rapid resonant mechanical scanning of the illumination beam coupled with highly sensitive, camera-based detection of the CARS signal allows for fast and direct hyperspectral wide-field image acquisition, while minimizing sample damage...
November 24, 2016: Scientific Reports
Jianwei Qin, Moon S Kim, Kuanglin Chao, Sagar Dhakal, Hoonsoo Lee, Byoung-Kwan Cho, Changyeun Mo
Milk is a vulnerable target for economically motivated adulteration. In this study, a line-scan high-throughput Raman imaging system was used to authenticate milk powder. A 5 W 785 nm line laser (240 mm long and 1 mm wide) was used as a Raman excitation source. The system was used to acquire hyperspectral Raman images in a wavenumber range of 103-2881 cm(-1) from the skim milk powder mixed with two nitrogen-rich adulterants (i.e., melamine and urea) at eight concentrations (w/w) from 50 to 10,000 ppm. The powdered samples were put in sample holders with a surface area of 150 mm×100 mm and a depth of 2 mm for push-broom image acquisition...
November 23, 2016: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
Koen Janssens, Geert Van der Snickt, Frederik Vanmeert, Stijn Legrand, Gert Nuyts, Matthias Alfeld, Letizia Monico, Willemien Anaf, Wout De Nolf, Marc Vermeulen, Jo Verbeeck, Karolien De Wael
Recent studies are concisely reviewed, in which X-ray beams of (sub)micrometre to millimetre dimensions have been used for non-destructive analysis and characterization of pigments, minute paint samples, and/or entire paintings from the seventeenth to the early twentieth century painters. The overview presented encompasses the use of laboratory and synchrotron radiation-based instrumentation and deals with the use of several variants of X-ray fluorescence (XRF) as a method of elemental analysis and imaging, as well as with the combined use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS)...
December 2016: Topics in Current Chemistry (Journal)
Taixia Wu, Guanghua Li, Zehua Yang, Hongming Zhang, Yong Lei, Nan Wang, Lifu Zhang
Spectral analysis is one of the main non-destructive techniques used to examine cultural relics. Hyperspectral imaging technology, especially on the shortwave infrared (SWIR) band, can clearly extract information from paintings, such as color, pigment composition, damage characteristics, and painting techniques. All of these characteristics have significant scientific and practical value in the study of ancient paintings and other relics and in their protection and restoration. In this study, an ancient painting, numbered Gu-6541, which had been found in the Forbidden City, served as a sample...
November 21, 2016: Applied Spectroscopy
Mihaela Antonina Calin, Sorin Viorel Parasca, Marian Romeo Calin, Emil Petrescu
Skin texture has become an important issue in recent research with applications in the cosmetic industry and medicine. In this paper, we analyzed the dependence of skin texture features on wavelength as well as on different parameters (age and gender) of human participants using grey-level co-occurrence matrix and hyperspectral imaging technique for a more accurate quantitative assessment of the aging process. A total of 42 healthy participants (men and women; age range, 20-70 years) was enrolled in this study...
November 21, 2016: Applied Spectroscopy
Kun Chen, Tao Wu, Haoyun Wei, Tian Zhou, Yan Li
Coherent anti-Stokes Raman microscopy (CARS) is a quantitative, chemically specific, and label-free optical imaging technique for studying inhomogeneous systems. However, the complicating influence of the nonresonant response on the CARS signal severely limits its sensitivity and specificity and especially limits the extent to which CARS microscopy has been used as a fully quantitative imaging technique. On the basis of spectral focusing mechanism, we establish a dual-soliton Stokes based CARS microspectroscopy and microscopy scheme capable of quantifying the spatial information of densities and chemical composition within inhomogeneous samples, using a single fiber laser...
October 1, 2016: Biomedical Optics Express
Jeong-Seok Cho, Hyung-Jin Bae, Byoung-Kwan Cho, Kwang-Deog Moon
Qualitative properties of roasting defect coffee beans and their classification methods were studied using hyperspectral imaging (HSI). The roasting defect beans were divided into 5 groups: medium roasting (Cont), under developed (RD-1), over roasting (RD-2), interior under developed (RD-3), and interior scorching (RD-4). The following qualitative properties were assayed: browning index (BI), moisture content (MC), chlorogenic acid (CA), trigonelline (TG), and caffeine (CF) content. Their HSI spectra (1000-1700nm) were also analysed to develop the classification methods of roasting defect beans...
April 1, 2017: Food Chemistry
Xiaojun Qiao, Jinbao Jiang, Xiaotong Qi, Haiqiang Guo, Deshuai Yuan
It's well-known fungi-contaminated peanuts contain potent carcinogen. Efficiently identifying and separating the contaminated can help prevent aflatoxin entering in food chain. In this study, shortwave infrared (SWIR) hyperspectral images for identifying the prepared contaminated kernels. Feature selection method of analysis of variance (ANOVA) and feature extraction method of nonparametric weighted feature extraction (NWFE) were used to concentrate spectral information into a subspace where contaminated and healthy peanuts can have favorable separability...
April 1, 2017: Food Chemistry
Qingyan Wang, Junping Zhang
Hyperspectral data provide new capabilities for discriminating spectrally similar classes, but such class signatures sometimes will be difficult to analyze. To incorporate reliable useful information could help, but at the same time, may also lead increased dimensionality of the feature vector making the hyperspectral data larger than expected. It is challenging to apply discriminative information from these training data to testing data that are not in the same feature space and with different data distributions...
November 14, 2016: Sensors
Mika Ishigaki, Akihito Nakanishi, Tomohisa Hasunuma, Akihiko Kondo, Tetsu Morishima, Toshiaki Okuno, Yukihiro Ozaki
In the present study, the high-speed quantitative evaluation of glycogen concentration accumulated in bioethanol feedstock Synechocystis sp. PCC6803 was performed using a near-infrared (NIR) imaging system with a hyperspectral NIR spectral camera named Compovision. The NIR imaging system has a feature for high-speed and wide area monitoring and the two-dimensional scanning speed is almost 100 times faster than the general NIR imaging systems for the same pixel size. For the quantitative analysis of glycogen concentration, partial least squares regression (PLSR) and moving window PLSR (MWPLSR) were performed with the information of glycogen concentration measured by high performance liquid chromatography (HPLC) and the calibration curves for the concentration within the Synechocystis sp...
November 16, 2016: Applied Spectroscopy
Xiangwei Zhao, Tengfei Ma, Zhaoyu Zeng, Shiya Zheng, Zhongze Gu
For multiplex bioassays, one effective strategy is to employ microfluidic chips based on an array of photonic crystal beads (PCBs) that are encoded by their characteristic reflection spectrum (CRS). In this paper, we report a hyperspectral imaging system and algorithms for the high throughput decoding of a PCB array and subsequent detection. The results showed that the decoding accuracy of up to ∼500 PCBs is 98.56% with an excellent ability to extract low-intensity fluorescence intensities. The results also demonstrated hyperspectral imaging techniques which can simultaneously obtain both spatial and spectral information as powerful tools in the analysis of multiplex bioassays or microfluidic chips...
November 11, 2016: Analyst
Robin Guay-Lord, Xavier Attendu, Kristen L Lurie, Lucas Majeau, Nicolas Godbout, Audrey K Ellerbee Bowden, Mathias Strupler, Caroline Boudoux
No abstract text is available yet for this article.
November 1, 2016: Journal of Biomedical Optics
Bryan D Maione, David Luo, Matthew Miskiewicz, Michael Escuti, Michael W Kudenov
Snapshot hyperspectral imaging Fourier transform (SHIFT) spectrometers are a promising technology in optical detection and target identification. For any imaging spectrometer, spatial, spectral, and temporal resolution, along with form factor, power consumption, and computational complexity are often the design considerations for a desired application. Motivated by the need for high spectral resolution systems, capable of real-time implementation, we demonstrate improvements to the spectral resolution and computation trade-space...
November 1, 2016: Applied Optics
Jing Zhang, Wenhao Geng, Li Zhuo, Qi Tian, Yan Cao
With the rapid growth of the capabilities for hyperspectral imagery acquisition, how to efficiently find the significant target in hyperspectral imagery has become a fundamental task for remote-sensing applications. Existing target extraction methods mainly separate targets from background with a threshold based on pixels and single-scale image information extraction. However, due to the high dimensional characteristics and the complex background of hyperspectral imagery, it is difficult to obtain good extraction results with existing methods...
October 1, 2016: Applied Optics
Xiang Li Zhong, Sibylle Schilling, Nestor J Zaluzec, M Grace Burke
In recent years, an increasing number of studies utilizing in situ liquid and/or gaseous cell scanning/transmission electron microscopy (S/TEM) have been reported. Because of the difficulty in the preparation of suitable specimens, these environmental S/TEM studies have been generally limited to studies of nanoscale structured materials such as nanoparticles, nanowires, or sputtered thin films. In this paper, we present two methodologies which have been developed to facilitate the preparation of electron-transparent samples from conventional bulk metals and alloys for in situ liquid/gaseous cell S/TEM experiments...
November 7, 2016: Microscopy and Microanalysis
Daniel Sydes, Pablo A Kler, Hans Meyer, Peter Zipfl, Daniel Lutz, Carolin Huhn
Monitoring analytes during the transfer step from the first to the second dimension in multidimensional electrophoretic separations is crucial to determine and control the optimal time point for sample transfer and thus to avoid band broadening or unwanted splitting of the sample band with consequent sample loss. A spatially resolved intermediate on-chip LED-induced fluorescence detection system was successfully implemented for a hybrid capillary-chip glass interface. The setup includes a high-power 455-nm LED prototype as an excitation light source and a linear light fiber array consisting of 23 light fibers with a diameter of 100 μm for spatially resolved fluorescence detection in combination with a push-broom imager for hyperspectral detection...
December 2016: Analytical and Bioanalytical Chemistry
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