scholarly journals Research into Methods for Determining Colour Differences in the CIELAB Uniform Colour Space

2020 ◽  
pp. 53-59
Author(s):  
Vera L. Zhbanova

A problem of qualitative determination of the results of colour image capturing by digital devices based on uniform colour systems arises during analysis of colour images. The article describes methods of determining colour difference as recommended by CIE for the CIELAB system, presents mathematical formulation of the system and its modifications, describes the programme developed for calculating colour difference for each described method, and describes testing of this programme using 14 sample colours from the Munsell Book of Colour. Three groups of red, green and blue filters with 7 filters in each were selected as the study object. The filters were selected based on possibility of their further application for determining colour shift by digital devices. Filter colour difference was studied in the groups with different standard sources of light and using three methods of calculation of this difference. Analysis of the obtained results is presented and conclusions are made on possibility to apply each method in different industrial spheres. The article may be useful for colour analysis specialists, quality inspectors and specialists in digital devices and computer vision.

2020 ◽  
pp. 86-94
Author(s):  
Vera L. Zhbanova

The research examined the changing of colour difference by the control colours depending on the choice of colour space when working with matrix photo detector. The spectral characteristics of photo detectors from different manufacturers noticeably differ from each other and from the addition the difference in colour quality between different digital devices. A software method for studying the colour rendition of the image obtained by digital devices based on the selection of an individual colour space for each matrix photo detector is proposed. To analyze and evaluate the capabilities of the spectral characteristics of matrix photo detectors, the control colour method based on the Mansell Atlas was used. The analysis of the obtained parameters of 14 colours was carried out according to various criteria for seven colour spaces: sRGB, AdobeRGB, DCI-P3 RGB, M1N1P1, PAL / SECAM, Wide Gamut RGB, ProPhoto RGB. Also studied the influence of the choice of colour space on the change in the coordinates of the source 6,500 K. Based on the colour differences of the control colours, it is possible to choose the optimal colour space for working with a specific matrix photo detector. The latter will reduce colour distortion at the initial stage of image registration. The ways for improving the colorimetric method of control colours are proposed as applied to digital devices at the software level.


1978 ◽  
Vol 39 (C6) ◽  
pp. C6-1232-C6-1233 ◽  
Author(s):  
N. F. Pedersen ◽  
J. Mygind ◽  
O. H. Soerensen ◽  
B. Dueholm

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.


2019 ◽  
Vol 2019 (1) ◽  
pp. 243-246
Author(s):  
Muhammad Safdar ◽  
Noémie Pozzera ◽  
Jon Yngve Hardeberg

A perceptual study was conducted to enhance colour image quality in terms of naturalness and preference using perceptual scales of saturation and vividness. Saturation scale has been extensively used for this purpose while vividness has been little used. We used perceptual scales of a recently developed colour appearance model based on Jzazbz uniform colour space. A two-fold aim of the study was (i) to test performance of recently developed perceptual scales of saturation and vividness compared with previously used hypothetical models and (ii) to compare performance and chose one of saturation and vividness scales for colour image enhancement in future. Test images were first transformed to Jzazbz colour space and their saturation and vividness were then decreased or increased to obtain 6 different variants of the image. Categorical judgment method was used to judge preference and naturalness of different variants of the test images and results are reported.


2017 ◽  
Vol 68 (4) ◽  
pp. 671-674
Author(s):  
Ana Maria Galan ◽  
Ioan Calinescu ◽  
Elena Radu ◽  
Elena Emilia Oprescu ◽  
Gabriel Vasilievici ◽  
...  

The purpose of this study was to develop a method for rapid quantitative and qualitative determination of the oil from microalgae lipid fraction obtained from Nannochloris sp biomass. The lipid fraction was first refluxed with 4% KOH in MeOH (60, 90, 120 min), followed by reaction with 20% BF3 in MeOH, using different times of reflux (90,120, 150 min) for each time of reflux with 4% KOH in MeOH. The FAME samples were analyzed by GC-MS analysis. 120 min reflux with 4% KOH in MeOH, 90 min with 20% BF3 in MeOH and a ratio lipid fraction: 4% KOH in MeOH: 20% BF3 in MeOH=1:20:27, were required to obtain the higher percent of oil in the microalgae lipid fraction. The relevance of the method developed was proved by TGA analysis and by transesterification of a sunflower oil sample in the same conditions.


2011 ◽  
Vol 35 (1) ◽  
pp. 16-24
Author(s):  
Lazem H. Al-Taie

Back ground: Toxoplasmosis is an important zoonosis that causes economic losses in animal herds due to abortion and stillbirth as well as changes in the reproductive and neural system of susceptible animals . Objective: The aims of the present study is to determination the prevalence of T. gondii in farm animals ( sheep& goat)of both genders and different ages in Sulaimani province by using two serological tests (ELISA and LAT). Methods: Blood samples were collected from farm animals ,142 sheep and 46 goats , of different sexes and ages. Tow different serological tests ,ELISA and LAT for qualitative determination of T. gondii antibody titer in sheep and goats serum samples. Results: The prevalence rate in sheep was 73 (51.7 %) and 82 (57 %) , and 21 (54.6 %) and 25 (54.35 %) in goats ,by ELISA and LAT respectively. The prevalence of toxoplasmosis was highest in age group 7-9 (66.6%) in sheep in compares’ with other age groups. There was no significant differences between both spp.and tow test. Conclusion: Statistical results show no significant differences between both tests (ELISA &LAT) at (P ≥ 0.05).The prevalence of toxoplasmosis was increased proportionally with the age of animals, while gender has no effect on the prevalent rate .


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