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hyperspectral imaging

Rebecca French, Sylvain Gigan, Otto L Muskens
Encoding of spectral information onto monochrome imaging cameras is of interest for wavelength multiplexing and hyperspectral imaging applications. Here, the complex spatiospectral response of a disordered material is used to demonstrate retrieval of a number of discrete wavelengths over a wide spectral range. Strong, diffuse light scattering in a semiconductor nanowire mat is used to achieve a highly compact spectrometer of micrometer thickness, transforming different wavelengths into distinct speckle patterns with nanometer sensitivity...
May 1, 2017: Optics Letters
Floréal Daniel, Aurélie Mounier, Josefina Pérez-Arantegui, Carlos Pardos, Nagore Prieto-Taboada, Silvia Fdez-Ortiz de Vallejuelo, Kepa Castro
The development of non-invasive techniques for the characterization of pigments is crucial in order to preserve the integrity of the artwork. In this sense, the usefulness of hyperspectral imaging was demonstrated. It allows pigment characterization of the whole painting. However, it also sometimes requires the complementation of other point-by-point techniques. In the present article, the advantages of hyperspectral imaging over point-by-point spectroscopic analysis were evaluated. For that purpose, three paintings were analysed by hyperspectral imaging, handheld X-ray fluorescence and handheld Raman spectroscopy in order to determine the best non-invasive technique for pigment identifications...
April 26, 2017: Analytical and Bioanalytical Chemistry
Sesha L A Paluri, John D Ryan, Nhi H Lam, Dhriti Nepal, Ioana E Sizemore
The clinical applications of silver nanoparticles (AgNPs) remain limited due to the lack of well-established methodologies for studying their nanokinetics. Hereby, the primary goal is to adapt a suite of analytical-based methodologies for examining the in vitro absorption, distribution, metabolism, and elimination of AgNPs. Vero 76 and HEK 293 cells are exposed to ≈10-nm spherical AgNPs(+) and AgNPs(-) at relevant concentrations (0-300 µg mL(-1) ) and times (4-48 h). Absorption: Inductively coupled plasma optical emission spectroscopy (ICP-OES) demonstrates that the two AgNP formulations are not bioequivalent...
April 25, 2017: Small
Pablo D Ruiz, Jonathan M Huntley
We describe a single-shot technique to measure areal profiles on optically smooth and stepped surfaces for applications where rapid data acquisition in non-cooperative environments is essential. It is based on hyperspectral interferometry (HSI), a technique in which the output of a white-light interferometer provides the input to a hyperspectral imaging system. Previous HSI implementations suffered from inefficient utilisation of the available pixels which limited the number of measured coordinates and/or unambiguous depth range...
April 17, 2017: Optics Express
Daniele Ravi, Himar Fabelo, Gustavo Marrero Callico, GuangZhong Yang
Recent advances in hyperspectral imaging have made it a promising solution for intra-operative tissue characterization, with the advantages of being non-contact, non-ionizing and non-invasive. Working with hyperspectral images in vivo, however, is not straightforward as the high dimensionality of the data makes real-time processing challenging. In this paper, a novel dimensionality reduction scheme and a new processing pipeline are introduced to obtain a detailed tumour classification map for intra-operative margin definition during brain surgery...
April 24, 2017: IEEE Transactions on Medical Imaging
Xiaoke Jin, Hafeezullah Memon, Wei Tian, Qinli Yin, Xiaofang Zhan, Chengyan Zhu
Synthetic fibers account for about half of all fiber usage, with applications in every textile field. The phenomenon of fiber composition not matching the label harms consumer interests and impedes market development. Hyperspectral imaging technology as a potential technique can be utilized to discriminate mass synthetic fibers rapidly and nondestructively and achieves the functions that traditional Fourier transform infrared instruments do not have. On the basis of investigating the impact of dope-dyeing and wrapping processes on spectra, the spectral features (from 900 to 2500 nm) of six categories of synthetic fibers were extracted with a hyperspectral imaging system...
April 20, 2017: Applied Optics
Maor Matzrafi, Ittai Herrmann, Christian Nansen, Tom Kliper, Yotam Zait, Timea Ignat, Dana Siso, Baruch Rubin, Arnon Karnieli, Hanan Eizenberg
Weed infestations in agricultural systems constitute a serious challenge to agricultural sustainability and food security worldwide. Amaranthus palmeri S. Watson (Palmer amaranth) is one of the most noxious weeds causing significant yield reductions in various crops. The ability to estimate seed viability and herbicide susceptibility is a key factor in the development of a long-term management strategy, particularly since the misuse of herbicides is driving the evolution of herbicide response in various weed species...
2017: Frontiers in Plant Science
Franziska R Winter, Maria Loidolt, Volker Westphal, Alexey N Butkevich, Carola Gregor, Steffen J Sahl, Stefan W Hell
The extension of fluorescence nanoscopy to larger numbers of molecular species concurrently visualized by distinct markers is of great importance for advanced biological applications. To date, up to four markers had been distinguished in STED experiments featuring comparatively elaborate imaging schemes and optical setups, and exploiting various properties of the fluorophores. Here we present a simple yet versatile STED design for multicolour imaging below the diffraction limit. A hyperspectral detection arrangement (hyperSTED) collects the fluorescence in four spectral channels, allowing the separation of four markers with only one excitation wavelength and a single STED beam...
April 18, 2017: Scientific Reports
Mohammed S Alshaykh, Chien-Sheng Liao, Oscar E Sandoval, Gregory Gitzinger, Nicolas Forget, Daniel E Leaird, Ji-Xin Cheng, Andrew M Weiner
Stimulated Raman scattering (SRS) is a powerful, label-free imaging technique that holds significant potential for medical imaging. To allow chemical specificity and minimize spectral distortion in the imaging of live species, a high-speed multiplex SRS imaging platform is needed. By combining a spectral focusing excitation technique with a rapid acousto-optic delay line, we demonstrate a hyperspectral SRS imaging platform capable of measuring a 3-dB spectral window of ∼200  cm<sup>-1</sup> within 12...
April 15, 2017: Optics Letters
Hyeon Jeong Lee, Delong Zhang, Ying Jiang, Xiangbing Wu, Pei-Yu Shih, Chien-Sheng Liao, Brittani Bungart, Xiao-Ming Xu, Ryan Drenan, Edward Bartlett, Ji-Xin Cheng
Detecting membrane potentials is critical for understanding how neuronal networks process information. We report a vibrational spectroscopic signature of neuronal membrane potentials identified through hyperspectral stimulated Raman scattering (SRS) imaging of patched primary neurons. High-speed SRS imaging allowed direct visualization of puff-induced depolarization of multiple neurons in mouse brain slices, confirmed by simultaneous calcium imaging. The observed signature, partially dependent on sodium ion influx, is interpreted as ion interactions on the CH3 Fermi resonance peak in proteins...
April 17, 2017: Journal of Physical Chemistry Letters
Derya Akkaynak, Liese A Siemann, Alexandra Barbosa, Lydia M Mäthger
Flounder change colour and pattern for camouflage. We used a spectrometer to measure reflectance spectra and a digital camera to capture body patterns of two flounder species camouflaged on four natural backgrounds of different spatial scale (sand, small gravel, large gravel and rocks). We quantified the degree of spectral match between flounder and background relative to the situation of perfect camouflage in which flounder and background were assumed to have identical spectral distribution. Computations were carried out for three biologically relevant observers: monochromatic squid, dichromatic crab and trichromatic guitarfish...
March 2017: Royal Society Open Science
Rosalba Calvini, Jose Manuel Amigo, Alessandro Ulrici
Due to the differences in terms of both price and quality, the availability of effective instrumentation to discriminate between Arabica and Robusta coffee is extremely important. To this aim, the use of multispectral imaging systems could provide reliable and accurate real-time monitoring at relatively low costs. However, in practice the implementation of multispectral imaging systems is not straightforward: the present work investigates this issue, starting from the outcome of variable selection performed using a hyperspectral system...
May 15, 2017: Analytica Chimica Acta
Mingyu Nie, Zhi Liu, Xiaofu He, Qingchen Qiu, Yuanyuan Zhang, Ju Chang
Hyperspectral images collected by a remote sensing hyperspectral imaging instrument have many mixed pixels, due to the limited resolution of image sensors and the complex diversity of nature. End-member extraction is the process that determines the end-members in mixed pixels. The results of traditional methods are inaccurate, due to the spatial complexity and noise of actual hyperspectral image data. This study presents segmented vertex component analysis (SVCA), wherein the relative complexities of hyperspectral images are segmented into a number of relatively simple spatial subsets to reduce the effect of uncorrelated pixels...
March 20, 2017: Applied Optics
Huajian Liu, Sang-Heon Lee, Javaan Singh Chahl
Images in red-green-blue (RGB) color space need to be transformed to other color spaces for image processing or analysis. For example, the well-known hue-saturation-intensity (HSI) color space, which separates hue from saturation and intensity and is similar to the color perception of humans, can aid many computer vision applications. For high-dimensional images, such as multispectral or hyperspectral images, transformation images to a color space that can separate hue from saturation and intensity would be useful; however, the related works are limited...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Hoong-Ta Lim, Vadakke Matham Murukeshan
Hyperspectral imaging is a combination of imaging and spectroscopy to give detailed spectral information for each spatial point in the imaged scene. Using the concept of integral field spectroscopy, a custom fabricated two-dimensional to one-dimensional fiber bundle has recently been reported. It is used as a flexible snapshot hyperspectral probe, which can be used as an endoscope for biomedical applications. This paper reports on the design considerations of the fiber bundle as the flexible probe in the snapshot hyperspectral imaging system...
March 2017: Review of Scientific Instruments
Jiyong Shi, Xuetao Hu, Xiaobo Zou, Jiewen Zhao, Wen Zhang, Mel Holmes, Xiaowei Huang, Yaodi Zhu, Zhihua Li, Tingting Shen, Xiaolei Zhang
Edible bird's nest (EBN) is a precious functional food in Southeast Asia. A rapid and nondestructive method for determining the distribution map of protein content (PC), carbohydrate content (CC) and sialic acid content (SAC) on EBN sample was proposed. Firstly, 60 EBNs were used for hyperspectral image acquisition, and components content (PC, CC and SAC) were determined by chemical analytical methods. Secondly, the spectral signals of EBN hyperspectral image and EBN components content were used to build calibration models...
August 15, 2017: Food Chemistry
Tarin Paz-Kagan, Tamir Caras, Ittai Herrmann, Moshe Shachak, Arnon Karnieli
Land-use changes are one of the most important factors causing environmental transformations and species diversity alterations. The aim of the current study was to develop a geoinformatics-based framework to quantify alpha and beta diversity indices in two sites in Israel with different land-uses, i.e., an agricultural system of fruit orchards, an afforestation system of planted groves, and an unmanaged system of groves. The framework comprises four scaling steps: (1) classification of a tree species distribution (SD) map using imaging spectroscopy (IS) at a pixel size of 1 m; (2) estimation of local species richness by calculating the alpha diversity index for 30-m grid cells; (3) calculation of beta diversity for different land-use categories and sub-categories at different sizes; and (4) calculation of the beta diversity difference between the two sites...
March 28, 2017: Ecological Applications: a Publication of the Ecological Society of America
Sen Jia, Linlin Shen, Jiasong Zhu, Qingquan Li
As manual labeling is very difficult and time-consuming, the labeled samples used to train a supervised classifier are generally limited, which become one of the biggest challenge for hyperspectral imagery classification. In order to tackle this issue, a recent trend is to exploit the structure information of materials, as which reflects the region homogeneity in the spatial domain and offers an invaluable complement to the spectral information. In this respect, 3-D Gabor wavelets have been introduced to extract joint spectral-spatial features for hyperspectral images...
March 28, 2017: IEEE Transactions on Cybernetics
Peter Lasch, Isao Noda
Hyperspectral imaging (HSI) techniques are useful for obtaining very detailed structural and compositional information from biomedical, pharmaceutical, or clinical samples, among others. The informative value of these methods can be further increased through the application of different HSI techniques and joint analysis of the data. However, interpretation and understanding of multimodal HSI have been impeded by difficulties in registration of the different HSI data sets and by the lack of integrative analysis concepts...
April 11, 2017: Analytical Chemistry
Gulsen Taskin Kaya, Huseyin Kaya, Lorenzo Bruzzone
In hyperspectral image analysis, the classification task has generally been addressed jointly with dimensionality reduction due to both the high correlation between the spectral features and the noise present in spectral bands which might significantly degrade classification performance. In supervised classification, limited training instances in proportion to the number of spectral features have negative impacts on the classification accuracy, which has known as Hughes effects or curse of dimensionality in the literature...
March 24, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
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