scholarly journals Color star tracking II: matching

2021 ◽  
Author(s):  
Geoffrey R. McVittie ◽  
John Enright
Keyword(s):  
Field Testing ◽  
Color Filter ◽  
Array Detector ◽  
Large Set ◽  
Blue Color ◽  
Matching Algorithm ◽  
Sensor Field ◽  
Electronic Copy ◽  
Star Tracking ◽  
Personal Use

A novel matching algorithm is presented that can identify stars using raw images of the sky obtained from a CMOS color filter array detector. The algorithm combines geometric information with amplitude ratios calculated from the red, green, and blue color color channels. Conventional algorithms that match stars based solely on inter-star geometry (and sometimes relative brightness), typically require three or more stars for a confident star match. In contrast, the presented algorithms are able to find matches with only two imaged stars in most regions of the sky. The necessary catalog preparation and a simple star-pair matching algorithm based on combined color intensity ratios and the angular spacing are discussed. Results from a large set of simulation trials and initial results from sensor field testing are presented.<div>Copyright 2013 Society of Photo‑Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, and modification of the contents of the publication are prohibited.<br></div><div><br><div><br></div></div>

scholarly journals Color star tracking II: matching

2021 ◽  
Author(s):  
Geoffrey R. McVittie
Keyword(s):  
Field Testing ◽  
Color Filter ◽  
Array Detector ◽  
Large Set ◽  
Blue Color ◽  
Matching Algorithm ◽  
Sensor Field ◽  
Filter Array ◽  
Star Tracking ◽  
Pair Matching

A novel matching algorithm is presented that can identify stars using raw images of the sky obtained from a CMOS color filter array detector. The algorithm combines geometric information with amplitude ratios calculated from the red, green, and blue color color channels. Conventional algorithms that match stars based solely on inter-star geometry (and sometimes relative brightness), typically require three or more stars for a confident star match. In contrast, the presented algorithms are able to find matches with only two imaged stars in most regions of the sky. The necessary catalog preparation and a simple star-pair matching algorithm based on combined color intensity ratios and the angular spacing are discussed. Results from a large set of simulation trials and initial results from sensor field testing are presented.

scholarly journals Color star tracking II: matching

2021 ◽  
Author(s):  
Geoffrey R. McVittie
Keyword(s):  
Field Testing ◽  
Color Filter ◽  
Array Detector ◽  
Large Set ◽  
Blue Color ◽  
Matching Algorithm ◽  
Sensor Field ◽  
Filter Array ◽  
Star Tracking ◽  
Pair Matching

A novel matching algorithm is presented that can identify stars using raw images of the sky obtained from a CMOS color filter array detector. The algorithm combines geometric information with amplitude ratios calculated from the red, green, and blue color color channels. Conventional algorithms that match stars based solely on inter-star geometry (and sometimes relative brightness), typically require three or more stars for a confident star match. In contrast, the presented algorithms are able to find matches with only two imaged stars in most regions of the sky. The necessary catalog preparation and a simple star-pair matching algorithm based on combined color intensity ratios and the angular spacing are discussed. Results from a large set of simulation trials and initial results from sensor field testing are presented.

DETERMINATION OF CHLORHEXIDINE DIGLUCONATE IN DISINFECTANTS

2018 ◽  
Vol 61 (8) ◽  
pp. 4
Author(s):  
Sergey V. Andreev ◽  
Evgeny S. Belyaev ◽  
Anna O. Ivanova ◽  
Elvina A. Novikova ◽  
Anatoly A. Ishchenko
Keyword(s):  
Bromophenol Blue ◽  
Array Detector ◽  
Diode Array ◽  
Blue Color ◽  
Chlorhexidine Digluconate ◽  
Diode Array Detector ◽  
Charged Aerosol ◽  
Charged Aerosol Detector ◽  
Wide Range

Chlorhexidine digluconate has been widely used in lenticular compositions, skin antiseptics and other ready-to-use disinfectants. This is due to its low toxicity, as well as a wide range of antimicrobial effects. A commonly used method for the analysis of commercially available chlorhexidine digluconate (usually available as a 20% aqueous solution) is high-performance liquid chromatography. In this article, the main methods of analysis used to determine chlorhexidine digluconate in disinfectants and skin antiseptics are considered. A new simple technique for the determination of chlorhexidine digluconate in technical products and disinfectants based on acid-base titration in alcohol-ketone is developed. It is shown that in this medium hydrochloric acid interacts with two nitrogen atoms of the chlorhexidine digluconate molecule. The end point of the titration is established by the transition of the blue color to green in the presence of bromophenol blue. The range of measured concentrations is from 0.1 to 2.0 mass%. The relative error of the method is 2.5% with the confidence probability P = 0.95. A comparison of the diode array detector and the charged aerosol detector for the determination of chlorhexidine digluconate has been performed. It is shown that a charged aerosol detector can be used to analyze chlorhexidine digluconate in cases where it is difficult to analyze with an ultraviolet or diode array detector. However, the sensitivity of the detector of charged aerosols is significantly lower than that of the diode matrix, and the linearity range is smaller. All methods were tested on model samples, as well as on samples of disinfectants, skin antiseptics, soaps and wipes with antibacterial effect.

Spectral Sensing of Asbestos According to Concentration in Various Asbestos Containing Materials

2014 ◽  
Vol 627 ◽  
pp. 7-11 ◽  
Author(s):  
Ho Sang Ahn ◽  
Byung Kwon Jung ◽  
Jin Chul Joo ◽  
Jae Ro Park
Keyword(s):  
Refractive Index ◽  
Optimum Condition ◽  
Wavelength Range ◽  
Building Materials ◽  
Asbestos Fiber ◽  
Color Filter ◽  
Particulate Matters ◽  
Blue Color ◽  
Experimental Conditions ◽  
Spectral Sensing

Asbestos in various building materials were measured by spectral sensor to examine the shift in reflectance wavelength according to asbestos concentration in different materials. Asbestos glove, asbestos soil, asbestos fiber insulation board, slate and bamlite panel were tested under several experimental conditions to alter reflectance intensity at each wavelength to find the optimum condition to detect asbestos selectively from other particulate matters. Chrysotile was found to have specific wavelength range regardless of concentration and type of materials as detected under blue color filter and dyed with refractive index liquid.

scholarly journals A Review on LBP in Image Retrieval System for Future Enhancement and Vector Images

2020 ◽  
pp. 155-161
Author(s):  
K Rajalakshmi ◽  
V Krishna Dharshini ◽  
S Selva Meena
Keyword(s):  
Image Retrieval ◽  
Image Database ◽  
Content Based Image Retrieval ◽  
Large Set ◽  
Query Image ◽  
Matching Algorithm ◽  
Image Retrieval System ◽  
Similar Images ◽  
Vector Images ◽  
Similar Kind

Content-Based Image Retrieval is a process to retrieve the similar images from the large set of image database corresponding to the query image. In CBIR low level or pixel level features such as color, texture and shape of the images are extracted and on the basis of similarity matching algorithm the required similar kind of images are retrieved from the image database. To understand the evaluation and evolution of CBIR system various research was studied and various research is going on this way also. In this paper, we have discussed some of the popular pixel level feature extraction techniques for Content-Based Image Retrieval and we also present here about the performance of each technique.

scholarly journals Understanding the structural degradation of South American historical silk: A Focal Plane Array (FPA) FTIR and multivariate analysis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Diego Badillo-Sanchez ◽  
David Chelazzi ◽  
Rodorico Giorgi ◽  
Alessandra Cincinelli ◽  
Piero Baglioni
Keyword(s):  
Multivariate Analysis ◽  
Focal Plane ◽  
Structural Changes ◽  
Structural Information ◽  
Focal Plane Array ◽  
Secondary Structures ◽  
Array Detector ◽  
Large Set ◽  
South American ◽  
Protein Secondary Structures

AbstractSilk artifacts constitute an invaluable heritage, and to preserve such patrimony it is necessary to correlate the degradation of silk fibroin with the presence of dyes, pollutants, manufacturing techniques, etc. Fourier Transform Infrared Spectroscopy with a Focal plane array detector (FPA FTIR) provides structural information at the micron scale. We characterized the distribution of secondary structures in silk fibers for a large set of South American historical textiles, coupling FTIR with multivariate statistical analysis to correlate the protein structure with the age of the samples and the presence of dyes. We found that the pressure applied during attenuated total reflectance (ATR) measurements might induce structural changes in the fibers, producing similar spectra for pristine and aged samples. Reflectance spectra were thus used for the rigorous characterization of secondary structures. Some correlation was highlighted between the age of the samples (spanning over five centuries) and specific changes in their secondary structure. A correlation was found between the color of the samples and structural alterations, in agreement with the chemical nature of the dyes. Overall, we demonstrated the efficacy of reflectance FPA µ-FTIR, combined with multivariate analysis, for the rigorous and non-invasive description of protein secondary structures on large sets of samples.

Man-Portable Laser-Induced Breakdown Spectroscopy System for in Situ Characterization of Karstic Formations

2008 ◽  
Vol 62 (11) ◽  
pp. 1250-1255 ◽  
Author(s):  
J. Cuñat ◽  
F. J. Fortes ◽  
L. M. Cabalín ◽  
F. Carrasco ◽  
M. D. Simón ◽  
...  
Keyword(s):  
Field Testing ◽  
Array Detector ◽  
Depth Information ◽  
Charge Coupled Device ◽  
Breakdown Spectroscopy ◽  
Ccd Array ◽  
Laser Induced Breakdown ◽  
Environment Identification ◽  
A Charge ◽  
Identification Analysis

This paper reports the development and field testing of a man-portable instrument based on laser-induced breakdown spectrometry (LIBS) for inspection and analysis of speleothems. The 50 mJ of a Q-switched Nd:YAG laser operating at 1064 nm was used to generate a plasma on the sample. Plasma emission was then guided using a fiber-optic cable to a 1/10 m spectrometer equipped with a charge-coupled device (CCD) array detector. Plasma light was automatically processed in order to obtain surface and in-depth information from the speleothems. A field campaign in the interior of Nerja Cave (a large karstic formation in the South of Spain) has been carried out, aimed at evaluating the analytical performance of the instrument when operating in an unfriendly environment. Identification analysis of the speleothems' alteration layers and depth profiles of Sr and Ca is carried out and reported.

scholarly journals High-Sensitivity Pixels with a Quad-WRGB Color Filter and Spatial Deep-Trench Isolation

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4653
Author(s):  
Yongnam Kim ◽  
Yunkyung Kim
Keyword(s):  
High Sensitivity ◽  
Image Sensor ◽  
Oxide Semiconductor ◽  
Color Filter ◽  
Limited Area ◽  
Blue Color ◽  
Pixel Size ◽  
Deep Trench ◽  
Filter Array ◽  
Trench Isolation

The demand for a high-resolution metal-oxide-semiconductor (CMOS) image sensor has increased in recent years, and pixel size has shrunk below 1.0 μm to allow accumulation of numerous pixels in a limited area. However, shrinking the pixel size lowers the sensitivity and increases crosstalk because the aspect ratio is worsened by maintaining the height of the pixel. This work introduces a high-sensitivity pixel with a quad-WRGB (White, Red, Green, Blue) color filter array (CFA), spatial deep-trench isolation (S-DTI), and a spatial tungsten grid (S-WG). The optical performance of the suggested pixel was analyzed by performing 3D optical simulations at 1.0, 0.9, and 0.8 μm pixel pitches as small-sized pixels. The quad-WRGB CFA is compared with the quad-Bayer CFA, and the S-DTI and S-WG are compared with the conventional DTI and WG. We confirmed an improvement in the sensitivity of the suggested pixel using the quad-WRGB CFA with S-DTI and S-WG to a maximum of 58.2%, 67.0%, and 66.3% for 1.0, 0.9, and 0.8 μm pixels, respectively.

Synthesis and Physical Properties of New Blue Color Filter Dye Using on Triarylmethine Moiety for Image Sensors

2021 ◽  
Vol 21 (9) ◽  
pp. 4675-4679
Author(s):  
Sunwoo Park ◽  
Yeonkyu Jeong ◽  
Seokwoo Kang ◽  
Sangshin Park ◽  
Hyukmin Kwon ◽  
...  
Keyword(s):  
Chemical Stability ◽  
High Performance ◽  
Color Difference ◽  
Image Sensor ◽  
Image Sensors ◽  
Color Filter ◽  
Blue Color ◽  
Migration Test ◽  
Before And After ◽  
Thermal And Chemical Stability

In this study, a triarylmethine derivative of DMCEBA-BTSA with the high thermal and chemical stability was newly synthesized in order to develop a high-performance image sensor. It showed a high transmittance of more than 80% at 450 nm and △Eab showed a very low color difference of 2.32 after thermal treatment. In solvent resistance, transmittance of 90% was not changed and △Eab showed a low color difference of 0.67 before and after solvent dipping. As a results of the migration test, there was no change at all after dipping in the PGMEA transmittance spectrum. It was confirmed that the newly synthesized blue colorant exhibited excellent thermal and chemical stability and it could be applied to image sensor color filter application as the blue color.

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