Color changes of ash wood (Fraxinus excelsior L.) caused by thermal modification in air and steam

2021 ◽  
Vol 116 ◽  
pp. 21-27
Author(s):  
Jakub Gawron ◽  
Monika Marchwicka
Keyword(s):  
Color Space ◽  
Color Difference ◽  
Thermal Modification ◽  
Fraxinus Excelsior ◽  
Space Model ◽  
Color Changes ◽  
Cielab Color Space ◽  
Before And After ◽  
Total Color Difference ◽  
Cielab Color

Color changes of ash wood (Fraxinus excelsior L.) caused by thermal modification in air and steam. Ash wood samples of 20x20x30 mm were subjected to thermal modification in different conditions. The thermal modification was conducted in air at 190 °C and in steam at 160 °C. For both environments modification lasted 2, 6 and 10 hours. Samples color parameters were measured before and after thermal modification on the basis of the mathematical CIELab color space model. Changes in all parameters (L, a and b) were observed, the highest in lightness (L) - darker color. The total color difference (ΔE) and chromaticity change (ΔC) were calculated for all samples. The highest value of ΔE was obtained for wood modified in the air at 190 °C for 10 h. The highest value of ΔC was obtained for wood modified in steam at 160 °C for 10 h. However, the value obtained for wood modified in the air at 190 °C for 10 h were only slightly lower.

Subjective Sensation of Color Differences – Determination of Thresholds Depending on Color Tones and Resolution

2015 ◽  
Vol 21 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Christian Brischke ◽  
Tanja Borcharding ◽  
Uta Mengel
Keyword(s):  
Color Space ◽  
Color Difference ◽  
Threshold Values ◽  
Color Tone ◽  
Color Changes ◽  
Art Objects ◽  
Color Differences ◽  
Subjective Sensation ◽  
Total Color Difference

Abstract Colors are frequently defined by three points on the L*a*b* coordinates of the CIELAB color space, and the distance between two colors can be expressed as the total color difference ΔE. In particular with respect to reproducibility of print media color differences are an important parameter, as well as for car finishes and textile dyes. Color changes are also the result of ageing and weathering which is an issue for art objects and in the building and restoration sector. However, the subjective perceptibility of color differences depends on numerous factors and general thresholds are difficult to define. This study aimed therefore on defining tolerance levels for color changes in dependence of color tones and color tone combinations as well as their resolution. In total 30 test persons evaluated samples, which had been painted with acrylic artist colors with defined color differences (ΔE = 0–7). The test subjects realized color differences already at ΔE = 1–4 for the highest resolution. Threshold values have been identified for different tones as well as the effect of interdependencies between tones and the level of color heterogeneity between adjacent areas.

scholarly journals The Role of Scale Adjustment in Color Change Evaluation

Instruments ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 42 ◽  
Author(s):  
Gueli ◽  
Pasquale ◽  
Politi ◽  
Stella
Keyword(s):  
Color Change ◽  
High Reliability ◽  
Research Work ◽  
Color Space ◽  
Color Difference ◽  
Color Measurement ◽  
Cielab Color Space ◽  
Archaeological Excavations ◽  
Cielab Color

The aim of this research work was to assess the influence of different scale adjustment conditions on both color measurement and color difference quantification and, in particular, to determine the best procedure to follow for a high-reliability protocol. This issue is very important in the Cultural Heritage field and, above all, in color measurement, which is carried out at different times during conservation and restoration campaigns or during archaeological excavations. Color change evaluation, performed by way of spectrophotometric measurements under different scale adjustment procedures on selected samples represented by colored reflectance standards and colored paintings, aimed to obtain results not only on ideal samples (certified standards) but also on real case studies (paintings). The study was conducted by focusing on the coordinates of the CIELAB color space and, in particular, on the calculation of the ΔE*ab quantity. The results show the introduction of nonsystematic variation with different scale adjustment procedures independent of materials and hue.

The Analysis for Evaluation of Ceramic Tile’s Color Difference Based on CIELAB Color Space

2012 ◽  
Vol 490-495 ◽  
pp. 3726-3732
Author(s):  
Zhe Min Dai ◽  
De Sheng Li ◽  
Hu Xie
Keyword(s):  
Quality Evaluation ◽  
Color Space ◽  
Great Influence ◽  
Color Difference ◽  
Evaluation Index ◽  
Ceramic Tiles ◽  
Cielab Color Space ◽  
Quality Testing ◽  
Different Color ◽  
Cielab Color

The color difference is one of the important evaluation index in ceramic tiles quality evaluation. So a good color difference evaluation index selecting has a great influence to the ceramic tile’s quality testing. In this paper, by computing and analyzing different color difference evaluation index, it is shown that CIE2000 formula is robust and feasible in ceramic tiles quality evaluation.

scholarly journals Quantitative Weathering Assessment of Rock Slope using CIELAB Color Space and Image Analysis Technique

2021 ◽  
Author(s):  
Mazlina Razali ◽  
Muhd Herman Jamal ◽  
Mohd Ashraf Mohamad Ismail ◽  
Intan Norsheira Yusoff ◽  
Sharan Kumar Nagendran ◽  
...  
Keyword(s):  
Image Analysis ◽  
Structural Control ◽  
Rock Slope ◽  
Color Space ◽  
Visual Assessment ◽  
Geological Structure ◽  
Color Changes ◽  
Cielab Color Space ◽  
Analysis Technique ◽  
Cielab Color

Abstract Quantitative weathering assessment using color changes is one of the new tools for slope stability assessment. In many other engineering field, CIELAB color space and image analytical tools have aided in enhancing the conventional method or inaccuracy due to the subjective and qualitative nature of visual assessment. This study focuses on the granitic rock slope surface assessment because of the predominant rock formation of granite in Malaysia. The 3D model of the rock slope was analyzed to extract the geological planes using compass plugin in Cloud Compare software and verified by manual compass mapping via scanline survey. Findings show that the a* and b* values increased with an increase in weathering results. This study focuses on the 50 points of measurement of rock slope and indicated a positive correlation of a* and b* with R2=0.9027. The image analysis result of the rock slope shows that major zoning (74%) is susceptible to failure due to structural control whilst another 26% are controlled by significant weathering in the grade IV-VI. This outcome is strongly verified via a geomechanical test, geological structure, and mineralogical assessment. The aforementioned mechanism is recommended in any geotechnical and technical purpose in enhancing the method of weathering assessment because image analysis provides reliable measurements in addition to the manual visual inspection.

A Discussion on Printing Color Difference Tolerance by CIEDE2000 Color Difference Formula

2012 ◽  
Vol 262 ◽  
pp. 96-99 ◽  
Author(s):  
Hao Xue Liu ◽  
Bing Wu ◽  
Yu Liu ◽  
Min Huang ◽  
Yan Fang Xu
Keyword(s):  
Color Space ◽  
Color Difference ◽  
Experimental Results ◽  
Printing Industry ◽  
Cielab Color Space ◽  
Difference Formula ◽  
Different Color ◽  
Cielab Color

In ISO printing standards, a color difference tolerance of ΔE*ab=5 is used as a threshold. But CIELAB color space is not uniform enough so that the same color difference value represents different color difference sensation in different color area. It is proved that the color difference calculated by CIEDE2000 is closer to the human sensation, so ISO TC130 is discussing the possibility of replacing CIELAB color difference by CIEDE2000. An experiment was conducted, in which the color difference of typical printing colors, CMYKRGB, was calculated and test. The experimental results showed that the color difference tolerance of ΔE*ab=5 is corresponding to 0.95~6.42 by CIEDE2000, with the average of 3.30 ΔE*00. So a color difference tolerance of ΔE*00=3.3 or a somewhat looser value of ΔE*00=3.5 can be adopted as a new tolerance for printing industry.

INFLUENCE OF THERMAL TREATMENT ON COLOUR PROPERTIES OF DRY POTATO PUREE

2018 ◽  
Author(s):  
И.М. ПОЧИЦКАЯ ◽  
Ю.Ф. РОСЛЯКОВ ◽  
В.В. ЛИТВЯК ◽  
Н.В. КОМАРОВА
Keyword(s):  
Color Change ◽  
Color Space ◽  
Color Difference ◽  
Treatment Temperature ◽  
Heating Process ◽  
Colour Properties ◽  
Color Changes ◽  
Organoleptic Characteristics ◽  
Before And After ◽  
Mashed Potatoes

Предложен способ оценки изменения цвета, основанный на обработке цифровых фотоизображений до и после температурно-временных воздействий. На основе полученных характеристик цветового пространства red–green–blue (RGB) был рассчитан показатель цветового различия ДE. Установлено, что с увеличением температуры термообработки образцов резко (на 50–80%) увеличивается значение цветовой разницы. При температуре 120°С значение цветовой разницы меняется незначительно и не превышает 15 единиц даже после 2-часового температурного воздействия. Однако при повышении температуры до 180–210°С цветовая разница за первые 10 мин увеличивается существенно и после 60 мин нагревания меняется незначительно. Проведенная оценка изменения цвета сухого картофельного пюре показала, что предлагаемый метод позволяет количественно оценить изменения цветовых характеристик продукта. Данная методика является чувствительной и более точной и дает возможность оценить не воспринимаемые человеком изменения цвета. Установлено следующее: контролируя температуру и длительность процесса нагревания, можно достичь желаемого цвета для сухого картофельного пюре, что напрямую влияет на его органолептические характеристики и потребительские свойства. A method for estimating the color change based on the processing of digital photo images before and after the temperature-time effects are proposed. Based on the received characteristics of the red–green–blue (RGB) color space, the color difference ДE was calculated. It is established that with increasing heat treatment temperature of the samples, the value of the color difference is sharply increased (by 50–80%). At a temperature of 120°C, the value of the color difference varies insignificantly and does not exceed 15 units even after a 2-hour exposure to temperature. However, with an increase in temperature 180–210°C, the color difference for the first 10 min increases substantially and after 60 minutes of heating changes insignificantly. The evaluation of the color change of dry mashed potatoes showed that the proposed method allows quantitative assessment of changes in color characteristics, is sensitive and more accurate, gives an opportunity to assess the color changes not perceived by a person. The received results demonstrate that controlling the temperature and duration of the heating process, it is possible to obtain the desired color of dry mashed potatoes, which is important, since color directly affects the organoleptic characteristics and consumer properties.

scholarly journals Drying of Steaming Maple Timber in Drying Kilns, While Preserving the Color Acquired by the Wood Steaming Process

2020 ◽  
Vol 328 ◽  
pp. 04004
Author(s):  
Ladislav Dzurenda
Keyword(s):  
Color Space ◽  
Free Water ◽  
Color Difference ◽  
Thermal Processes ◽  
Drying Process ◽  
Negative Aspect ◽  
Drying Time ◽  
Color Changes ◽  
The Difference ◽  
Total Color Difference

The paper presents a mode for drying steaming maple timber of thickness h = 38 mm from moisture W1 = 50 % to W2 = 10 %, while preserving the color of wood obtained by the steaming process. The drying process is divided into two parts. Evaporation of free water from wet wood at drying medium temperatures td = 35 - 40 °C and evaporation of water from wood below the hygroscopicity limit W ≤ 25 % at drying medium temperatures td = 70 - 80 °C. Total color difference ΔE* determined by the difference in values on the CIE L*a*b* color space coordinates dried by the proposed mode for steaming maple timber and the reference values ΔE* = 1.03. According to the categorization of wood color changes in thermal processes by work (Cividini et al. (2007), this change belongs to the category of small color changes. A negative aspect of this drying mode is the approx. 25 % increase in timber drying time.

scholarly journals A Study of Automatic Judgment of Food Color and Cooking Conditions with Artificial Intelligence Technology

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1128
Author(s):  
Chern-Sheng Lin ◽  
Yu-Ching Pan ◽  
Yu-Xin Kuo ◽  
Ching-Kun Chen ◽  
Chuen-Lin Tien
Keyword(s):  
Artificial Intelligence ◽  
Image Processing ◽  
Color Space ◽  
Color Difference ◽  
Color Space Conversion ◽  
Before And After ◽  
Artificial Intelligence Technology ◽  
Artificial Intelligence Algorithm ◽  
Time Image ◽  
Cooking Conditions

In this study, the machine vision and artificial intelligence algorithms were used to rapidly check the degree of cooking of foods and avoid the over-cooking of foods. Using a smart induction cooker for heating, the image processing program automatically recognizes the color of the food before and after cooking. The new cooking parameters were used to identify the cooking conditions of the food when it is undercooked, cooked, and overcooked. In the research, the camera was used in combination with the software for development, and the real-time image processing technology was used to obtain the information of the color of the food, and through calculation parameters, the cooking status of the food was monitored. In the second year, using the color space conversion, a novel algorithm, and artificial intelligence, the foreground segmentation was used to separate the vegetables from the background, and the cooking ripeness, cooking unevenness, oil glossiness, and sauce absorption were calculated. The image color difference and the distribution were used to judge the cooking conditions of the food, so that the cooking system can identify whether or not to adopt partial tumbling, or to end a cooking operation. A novel artificial intelligence algorithm is used in the relative field, and the error rate can be reduced to 3%. This work will significantly help researchers working in the advanced cooking devices.

Evaluation of change in color of denim fabric after various industrial washing processes with different fiber composition

2014 ◽  
Vol 11 (2) ◽  
pp. 107-110
Author(s):  
Mushtaq Mangat ◽  
A. Abbasi ◽  
Jakub Wiener
Keyword(s):  
Color Space ◽  
Color Difference ◽  
Fiber Composition ◽  
Obvious Change ◽  
Washing Machines ◽  
Difference Formula ◽  
Denim Fabric ◽  
Cielab Color

Traditional denim made by using 100% cotton and novel denim made by using cotton in warp and spun PP in the weft were treated in 11 different ways on industrial garment washing machines with the help of various textile auxiliaries and pumice. There is an obvious change in color of denim. This change was measured by using Spectrophotometer. Reflectance was taken as a variable to observe the intensity of change. Color difference was measured by using the CIELab color difference formula 1976. Color space coordinates (L*, a*, b*) and color difference ΔE were calculated between the untreated denim and treated denim.

Changes in the content of chlorophylls and carotenoids in the rind of Fino 49 lemons during maturation and their relationship with parameters from the CIELAB color space

2019 ◽  
Vol 243 ◽  
pp. 252-260 ◽  
Author(s):  
A. Conesa ◽  
F.C. Manera ◽  
J.M. Brotons ◽  
J.C. Fernandez-Zapata ◽  
I. Simón ◽  
...  
Keyword(s):  
Color Space ◽  
Cielab Color Space ◽  
Cielab Color
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