scholarly journals Application of a Novel Low-Cost Hyperspectral Imaging Setup Operating in the Mid-Infrared Region

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 800 ◽  
Author(s):  
Jakob Kilgus ◽  
Robert Zimmerleiter ◽  
Kristina Duswald ◽  
Florian Hinterleitner ◽  
Gregor Langer ◽  
...  
Keyword(s):  
Hyperspectral Imaging ◽  
Low Cost ◽  
Infrared Region ◽  
Spatially Resolved ◽  
Spectral Identification ◽  
Fabry Perot ◽  
Imaging Approach ◽  
Reflection Geometry ◽  
Fingerprint Region ◽  
Working Distance

In this contribution, we demonstrate the realization and application of a low-cost, flexible, small and fast hyperspectral imaging approach operating in the midinfrared fingerprint region where most molecules exhibit their fundamental vibrations. Following this approach, the recording of chemical images of macroscopic-sized samples at standoff distances in reflection geometry is possible. The optical setup is based on spectral identification by means of a MEMS-based Fabry-Pérot interferometer combined with 2D-snapshot spatial resolution using a bolometer camera. Results show the successful spatially resolved (resolution below 500 µm) chemical identification of different samples deposited on a metal surface (FOV = 6 × 5 cm) at a working distance of 35 cm.

An electrically controlled liquid crystal Fabry-Perot hyperspectral imaging chip in mid-infrared region

2013 ◽  
Author(s):  
Anbang Fu ◽  
Huaidong Zhang ◽  
Xinyu Zhang ◽  
Hongshi Sang ◽  
Changsheng Xie
Keyword(s):  
Liquid Crystal ◽  
Hyperspectral Imaging ◽  
Infrared Region ◽  
Mid Infrared ◽  
Fabry Perot

scholarly journals Identification of Apple Varieties Using a Multichannel Hyperspectral Imaging System

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5120 ◽  
Author(s):  
Yuping Huang ◽  
Yutu Yang ◽  
Ye Sun ◽  
Haiyan Zhou ◽  
Kunjie Chen
Keyword(s):  
Hyperspectral Imaging ◽  
Spectral Range ◽  
Near Infrared ◽  
Imaging System ◽  
Visible Region ◽  
Infrared Region ◽  
Apple Variety ◽  
Apple Varieties ◽  
Spatially Resolved ◽  
Variety Classification

This paper reports the nondestructive detection of apple varieties using a multichannel hyperspectral imaging system consisting of an illumination fiber and 30 detection fibers arranged at source–detector distances of 1.5–36 mm over the spectral range of 550–1650 nm. Spatially resolved (SR) spectra were obtained for 1500 apples, 500 each of three varieties from the same orchard to avoid environmental and geographical influences. Partial least squares discriminant analysis (PLSDA) models were developed for single SR spectra and spectral combinations to compare their performance of variety detection. To evaluate the effect of spectral range on variety detection, three types of spectra (i.e., visible region: 550–780 nm, near-infrared region: 780–1650 nm, full region: 550–1650 nm) were analyzed and compared. The results showed that the single SR spectra presented a different accuracy for apple variety classification, and the optimal SR spectra varied with spectral types. Spectral combinations had better accuracies for variety detection with best overall classifications of 99.4% for both spectral ranges in the NIR and full regions; however, the spectral combination could not improve the results over the optimal single SR spectra in the visible region. Moreover, the recognition of golden delicious (GD) was better than those of the other two varieties, with the best classification accuracy of 100% for three types of spectra. Overall, the multichannel hyperspectral imaging system provides more spatial-spectral information for the apples, and the results demonstrate that the technique gave excellent classifications, which suggests that the multichannel hyperspectral imaging system has potential for apple variety detection.

An easy and low-cost biomagnetic methodology to study regional gastrointestinal transit in rats

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Leonardo Pinto ◽  
Guilherme Soares ◽  
André Próspero ◽  
Erick Stoppa ◽  
Gabriel Biasotti ◽  
...  
Keyword(s):  
Low Cost ◽  
Gastrointestinal Transit ◽  
Alternate Current ◽  
Phenol Red ◽  
Distal Small Intestine ◽  
Reliable Assessment ◽  
Imaging Approach ◽  
Magnetic Tracer ◽  
Tracer Distribution ◽  
Gi Transit

Abstract The identification of gastrointestinal (GI) motility disorders requires the evaluation of regional GI transit, and the development of alternative methodologies in animals has a significant impact on translational approaches. Therefore, the purpose of this study was to validate an easy and low-cost methodology (alternate current biosusceptometry – ACB) for the assessment of regional GI transit in rats through images. Rats were fed a test meal containing magnetic tracer and phenol red, and GI segments (stomach, proximal, medial and distal small intestine, and cecum) were collected to assess tracer’s retention at distinct times after ingestion (0, 60, 120, 240, and 360 min). Images were obtained by scanning the segments, and phenol red concentration was determined by the sample’s absorbance. The temporal retention profile, geometric center, gastric emptying, and cecum arrival were evaluated. The correlation coefficient between methods was 0.802, and the temporal retention of each segment was successfully assessed. GI parameters yielded comparable results between methods, and ACB images presented advantages as the possibility to visualize intrasegmental tracer distribution and the automated scan of the segments. The imaging approach provided a reliable assessment of several parameters simultaneously and may serve as an accurate and sensitive approach for regional GI research in rats.

Evaluation of melon drying using hyperspectral imaging technique in the near infrared region

LWT ◽  
2021 ◽  
Vol 143 ◽  
pp. 111092
Author(s):  
Jose Marcelino S. Netto ◽  
Fernanda A. Honorato ◽  
Patrícia M. Azoubel ◽  
Louise E. Kurozawa ◽  
Douglas F. Barbin
Keyword(s):  
Hyperspectral Imaging ◽  
Near Infrared ◽  
Imaging Technique ◽  
Infrared Region ◽  
Near Infrared Region

scholarly journals A 300-GHz low-cost high-gain fully metallic Fabry–Perot cavity antenna for 6G terahertz wireless communications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basem Aqlan ◽  
Mohamed Himdi ◽  
Hamsakutty Vettikalladi ◽  
Laurent Le-Coq
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Frequency Selective Surface ◽  
High Gain ◽  
Wireless Communication Systems ◽  
Beam Radiation ◽  
Compact Size ◽  
Fabry Perot ◽  
Operating Bandwidth ◽  
Polarization Level

AbstractA low-cost, compact, and high gain Fabry–Perot cavity (FPC) antenna which operates at 300 GHz is presented. The antenna is fabricated using laser-cutting brass technology. The proposed antenna consists of seven metallic layers; a ground layer, an integrated stepped horn element (three-layers), a coupling layer, a cavity layer, and an aperture-frequency selective surface (FSS) layer. The proposed aperture-FSS function acts as a partially reflective surface, contributing to a directive beam radiation. For verification, the proposed sub-terahertz (THz) FPC antenna prototype was developed, fabricated, and measured. The proposed antenna has a measured reflection coefficient below − 10 dB from 282 to 304 GHz with a bandwidth of 22 GHz. The maximum measured gain observed is 17.7 dBi at 289 GHz, and the gain is higher than 14.4 dBi from 285 to 310 GHz. The measured radiation pattern shows a highly directive pattern with a cross-polarization level below − 25 dB over the whole band in all cut planes, which confirms with the simulation results. The proposed antenna has a compact size, low fabrication cost, high gain, and wide operating bandwidth. The total height of the antenna is 1.24 $${\lambda }_{0}$$ λ 0 ($${\lambda }_{0}$$ λ 0 at the design frequency, 300 GHz) , with a size of 2.6 mm × 2.6 mm. The proposed sub-THz waveguide-fed FPC antenna is suitable for 6G wireless communication systems.

Design and fabrication of a high gain, low cost, LHCP Fabry‐Perot antenna at Ku band

2018 ◽  
Vol 61 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Yousef Azizi ◽  
Nader Komjani ◽  
Majid Karimipour
Keyword(s):  
Low Cost ◽  
High Gain ◽  
Fabry Perot ◽  
Ku Band

scholarly journals ACCURACY ASSESSMENT OF UNDERWATER PHOTOGRAMMETRIC THREE DIMENSIONAL MODELLING FOR CORAL REEFS

2016 ◽  
Vol XLI-B5 ◽  
pp. 821-828 ◽  
Author(s):  
T. Guo ◽  
A. Capra ◽  
M. Troyer ◽  
A. Gruen ◽  
A. J. Brooks ◽  
...  
Keyword(s):  
Coral Cover ◽  
Accuracy Assessment ◽  
Low Cost ◽  
Three Dimensional ◽  
Point Clouds ◽  
3D Modelling ◽  
Relative Accuracy ◽  
3D Point Clouds ◽  
The Individual ◽  
Working Distance

Recent advances in automation of photogrammetric 3D modelling software packages have stimulated interest in reconstructing highly accurate 3D object geometry in unconventional environments such as underwater utilizing simple and low-cost camera systems. The accuracy of underwater 3D modelling is affected by more parameters than in single media cases. This study is part of a larger project on 3D measurements of temporal change of coral cover in tropical waters. It compares the accuracies of 3D point clouds generated by using images acquired from a system camera mounted in an underwater housing and the popular GoPro cameras respectively. A precisely measured calibration frame was placed in the target scene in order to provide accurate control information and also quantify the errors of the modelling procedure. In addition, several objects (cinder blocks) with various shapes were arranged in the air and underwater and 3D point clouds were generated by automated image matching. These were further used to examine the relative accuracy of the point cloud generation by comparing the point clouds of the individual objects with the objects measured by the system camera in air (the best possible values). Given a working distance of about 1.5 m, the GoPro camera can achieve a relative accuracy of 1.3 mm in air and 2.0 mm in water. The system camera achieved an accuracy of 1.8 mm in water, which meets our requirements for coral measurement in this system.

SmartKC

2021 ◽  
Vol 5 (4) ◽  
pp. 1-27
Author(s):  
Siddhartha Gairola ◽  
Murtuza Bohra ◽  
Nadeem Shaheer ◽  
Navya Jayaprakash ◽  
Pallavi Joshi ◽  
...  
Keyword(s):  
Low Cost ◽  
Pearson Correlation ◽  
Step Method ◽  
Middle Income ◽  
Middle Income Countries ◽  
Large Populations ◽  
Pixel Location ◽  
3D Printed ◽  
Working Distance ◽  
Fitting In

Keratoconus is a severe eye disease affecting the cornea (the clear, dome-shaped outer surface of the eye), causing it to become thin and develop a conical bulge. The diagnosis of keratoconus requires sophisticated ophthalmic devices which are non-portable and very expensive. This makes early detection of keratoconus inaccessible to large populations in low-and middle-income countries, making it a leading cause for partial/complete blindness among such populations. We propose SmartKC, a low-cost, smartphone-based keratoconus diagnosis system comprising of a 3D-printed placido's disc attachment, an LED light strip, and an intelligent smartphone app to capture the reflection of the placido rings on the cornea. An image processing pipeline analyzes the corneal image and uses the smartphone's camera parameters, the placido rings' 3D location, the pixel location of the reflected placido rings and the setup's working distance to construct the corneal surface, via the Arc-Step method and Zernike polynomials based surface fitting. In a clinical study with 101 distinct eyes, we found that SmartKC achieves a sensitivity of 87.8% and a specificity of 80.4%. Moreover, the quantitative curvature estimates (sim-K) strongly correlate with a gold-standard medical device (Pearson correlation coefficient = 0.77). Our results indicate that SmartKC has the potential to be used as a keratoconus screening tool under real-world medical settings.

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