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1.
H. Lin M. R. Luo L. W. MacDonald A. W. S. Tarrant 《Color research and application》2001,26(4):270-277
A colour‐naming model was developed to categorize volumes for each of the 11 basic names in CIELAB colour space. This was tested with three different sets of data for two languages (English and Mandarin), derived from extensive colour categorization experiments. The performance of the model in predicting colour names was satisfactory, with an average prediction error of 8.3%. © 2001 John Wiley & Sons, Inc. Col Res Appl, 26, 270–277, 2001 相似文献
2.
Dong‐Ho Kim 《Color research and application》2015,40(1):17-29
A new colour space, named ULAB, is developed. It is derived from the CIELAB colour space and can be converted to and from CIELAB. Unlike modified CIELAB colour‐difference formulae, ULAB incorporates corrections for lightness, chroma, and hue differences into its colour coordinates. For the small magnitude colour difference data, it shows the performance as good as more complicated formulae such as CIEDE2000. ULAB shows another chance of developing a colour space approximately more uniform than CIELAB. © 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 17–29, 2015 相似文献
3.
An experimental approach is described for measuring colour discrimination thresholds of human observers. Special software was developed for the accurate display of colour pairs on a high resolution CRT, using serial feedback from a spectroradiometer. Discrimination thresholds between a test and a target colour are determined by repeatedly showing an observer a circle composed of four separate quadrants, one of which has a different colour from the other three. Three quadrants are of the test colour and one of the target colour, or vice versa. Observers are asked to select the quadrant that differs from the others. An experiment is described where hue‐dependent effects affecting hue discrimination are investigated. Eighteen hue threshold values around the hue circle, at constant L = 51 and C = 25, were measured for three observers. Hue thresholds were found to vary around the hue circle, exhibiting an abrupt change in the blue to purple region (240° ≤ hab,10 = 300°) This change is not fully accounted for by any CIELAB‐based colour difference formula, including the most recent CIEDE2000 formula. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 410–415, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20153 相似文献
4.
The appearance of human dentition is important both psychologically and commercially. Many people perceive the lightness and chromaticity of their teeth as key factors in their overall appearance leading to large businesses in materials for colour‐matched fillings and crowns and in tooth whitening products. The human eye is very sensitive to small colour differences, recognizing a row of highly colour‐matched crowns as unnatural yet seeing excessive colour variation or darkness as unattractive. One cause of tooth discolouration is a darkening of the dentine, visible through the enamel. This has lead the authors to develop a model capable of relating ( ) measurements on a scattering surface, in our case dentine, to ( ) measurements when overlaid by a translucent scattering layer, in our case tooth enamel. The model can be used when any scattering layer is superimposed on a coloured surface. In contrast to existing models, no spectral measurements are necessary allowing the use of colourimeters rather than spectrophotometers. However, there are limitations on the degree of colour saturation for both the coloured surface and the scattering layer as the model uses an approximation valid only for weakly saturated colours. As neither the enamel nor the dentine have strongly saturated colouration, the limitation is entirely acceptable for our work. The use of ( ) measurements directly rather than having to measure the spectrum of reflected light is of practical importance as such measurements in a dental surgery are impossible in all but exceptional cases whilst ( ) measurements in the surgery are routine. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 504–517, 2015 相似文献
5.
R. Huertas A. Yebra M.M. Prez M. Melgosa A.I. Negueruela 《Color research and application》2003,28(6):473-479
Spectroradiometric color measurements were performed at 26 regularly spaced points of a standard wine sampler into which 100 cc of wine were poured. Our goal is to describe the color changes occurring in this system, but not to propose a new method for wine‐color measurement. Three samples of three different wines (red, rosé and white) were studied. From experimental measurements, lines of constant lightness (L), chroma (C,10) and hue‐angle (hab,10) were plotted for each wine poured into the wine sampler, as well as lines of constant CIELAB color differences (ΔE,10), with respect to a reference point placed at the axis of the wine sampler and at the zone with the greatest diameter. Considering different points of the wine sampler, the color attribute undergoing the greatest change was lightness (ΔL about 16.0, 15.0 and 11.0 for the red, rosé and white wines, respectively), followed by chroma (ΔC,10 about 2.8, 3.8 and 2.6 for the red, rosé and white wines, respectively) and hue(ΔH,10 lower than 1.0 for all the wines). Lightness variations were related mainly to the thickness differences between various zones of the wine sampler. Large color differences were found among the different points of the wine poured into the wine sampler (about 20.0, 21.0 and 14.0 CIELAB units, for the red, rosé and white wines, respectively). Panels should be aware of these large color variations when wine is visually assessed using standard wine samplers. It should be concluded that a single color specification for a wine poured into a wine sampler gives incomplete information, but hue, which is the main color attribute considered by observers, is nearly constant in the wine sampler. © 2003 Wiley Periodicals, Inc. Col Res Appl, 28, 473–479, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10200 相似文献
6.
Chris Glasbey Gerie van der Heijden Vivian F. K. Toh Alision Gray 《Color research and application》2007,32(4):304-309
We propose a method for identifying a set of colours for displaying 2D and 3D categorical images when the categories are unordered labels. The principle is to find maximally distinct sets of colours. We either generate colours sequentially, to maximize the dissimilarity or distance between a new colour and the set of colours already chosen, or use a simulated annealing algorithm to find a set of colours of specified size. In both cases, we use a Euclidean metric on the perceptual colour space, CIELAB, to specify distances. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 304–309, 2007 相似文献
7.
Juana Fernndez&#x;Lpez Jos Angel Prez&#x;Alvarez Vicente Aranda&#x;Catal 《Color research and application》2000,25(5):376-380
Although the colour of different meat products has been studied, particularly in the final product , these studies do not separate the influence of degree of mincing from other factors such as additives, spices, manufacturing process, etc. The effect of degree of mincing on colour (CIELAB colour space) in pork meat was studied. Three mincing processes were studied, two using a grinder with 10 and 20 mm diameter holes in the plate, and a third in which a cutter was used to obtain a finely minced product. As control, intact meat was used. Colour parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, and colour differences], pH, and water holding capacity were determined. Mincing, regardless of the type used, increased the values of L*, b*, and H*, but decreased the values of a* and a*/b* ratio. The L* values increased with mincing degree. The H* values and a*/b* ratio of plate minced meats (10 and 20 mm) differed from that which had been finely minced. The mincing process did not modify the saturation values of the batters. Only the fine mincing process modified (increased) the water holding capacity of the batters. © 2000 John Wiley & Sons, Inc. Col Res Appl, 25, 376–380, 2000 相似文献
8.
M. Soriano M. Snchez‐Maran M. Melgosa E. Gmiz R. Delgado 《Color research and application》2002,27(6):430-440
Commercial talcs are pulverized mineral products with a variable chemical and mineralogic composition, widely used in industry. Although generally white, they have color variations. The aim of this study was to establish relationships between color parameters and the chemical and mineralogic composition of commercial talc samples, in order to investigate the causes of color. Chlorite, dolomite, magnesite, and calcite were the most abundant accessory minerals. Fe, Mn, Ti, and Ni were the most abundant chromophore chemical elements. Factor statistical analysis (89.8% of total variance explained) revealed that the influence of each mineral species on the different color parameters a*, b*, and L* is well defined (the highest loading factors). Chlorite associated with Fe, Mn, Ti, Zr, Cu, Zn, and V, and calcite associated with Zn, Cu, Sr (and, to a lesser degree, Fe, Mn, Ni, and Co) affect the color parameters a* and b* by inducing chromatic variations (greening and yellowing). Dolomite and magnesite associated with Fe, Sr, Ni, Co, V (and, to a lesser extent, Mn and Cu) affect L* by inducing darkening. 相似文献
9.
The perception and understanding of the three color attributes have been analyzed from two experiments using pairs of Munsell samples, where only one of the three color attributes were changed/unchanged (Experiment I/II) at a time. In each experiment, 36 pairs with color differences of 3 different sizes (average values of 15.8 and 21.7 CIELAB units for Experiments I and II, respectively) were assessed under standardized conditions by 40 normal observers, 20 of them with previous knowledge and experience in colorimetry. At a 95% confidence level, the results from the two experiments were not significantly different, indicating that color attributes were not easily distinguished: for example, for experienced observers, the percentage of correct answers for identifying the color attribute responsible for a color difference was only 72.4%, the random probability being 33.3%. There were no significant differences between the results found by men and women. The worst distinguished attribute was Chroma, that is, the least frequent confusion was between Hue and Value or vice versa. Value differences were more easily detected for achromatic than for chromatic pairs, both for experienced and inexperienced observers. With respect to the size of the color differences, we observed that large hue differences were more easily identifiable than smaller ones, and a constant Hue was more identifiable when the entire color difference was small. © 2000 John Wiley & Sons, Inc. Col Res Appl, 25, 356–367, 2000 相似文献
10.
The aim of this study was to use a minimum number of measured colour patches to evaluate the colour gamut of an n‐colour printing process. Traditionally, the colour gamut of a printing system has been derived by printing and then measuring a gamut target for example, a profiling chart. For an n‐colour printing (printing with more than four process inks), it is desirable to know the colour gamut of the given set of inks without having to print a large number of test patches. Different spectral printer models were used to predict the gamut of a 7‐colour printing process. The colorant space was divided into sectors each containing four inks. For each printer model, the colour gamut of the each four‐ink sector was predicted. All sector‐gamuts were then combined to predict the overall colour gamut of the n‐colour process. This predicted gamut was then compared with the gamut obtained by measurement using a gamut comparison index (GCI). The Yule–Nielsen modified spectral Neugebauer (YNSN) model gave the best accuracy, at the cost of a larger number of input measurements, than other models. A combination of the Kubelka–Munk (KM) and YNSN models performed well with the fewest input measurements. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 408–415, 2015 相似文献
11.
The aim of this work was to explore the limits of memory for the hue of coloured illumination using nonspectral colours. Eighty‐four undergraduate optometry students with normal colour vision as assessed by the Ishihara 38 plate test, were given 10 s to memorize the hue of a luminous surface (luminance 120 cd m?2), subtending 22 by 18 degrees in an otherwise unlit room. The sample hue was one of 12 samples with chromaticity spaced evenly every 30 degrees around a hue circle in the CIE UCS diagram. The circle, radius 0.06, was centered at the chromaticity of D65 (u′ = 0.198, v′ = 0.468). The hue was displaced randomly by between 40 and 100 degrees, and the participants were required to use one of two keys to return the hue to its original appearance. The keys changed CIE 1976 hue angle (huv) by 1 degree, one in a clockwise and the other in a counterclockwise direction, but left the CIE 1976 saturation (suv) and the luminance unchanged. Each participant saw the to‐be‐memorized hue once only and made subsequent adjustments without seeing it again. Four adjustments were made immediately, four after 1 h, and a further four after 1 week. The second and the fourth in each set of four were preceded by a clockwise displacement of hue angle and the remaining two by an anticlockwise displacement. The CIE 1976 UCS chromaticity of the standard and the chromaticity of the very first adjustment performed immediately after the presentation of the standard were separated by 0.0210 (s.d. 0.0178) averaged across hues. One hue (purple) was more readily nameable than the others and was more accurately reproduced. There was no evidence of stable individual differences in observers' memory: observers' accuracy in reproducing one colour was not significantly correlated with their accuracy in reproducing another. Adjustments made after an interval of 1 h were worse than those undertaken immediately, but no better than those performed after 1 week. The variability of hue memory under these conditions was similar to the variability of coloured surfaces under common sources of illumination. © 2006 Wiley Periodicals, Inc. Col Res Appl, 32, 11–15, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20281 相似文献
12.
Lewis D. Griffin Alastair G. Sutcliffe Kimberley Bradbury Smitha Kumble Dimitris Mylonas Alastair Baker 《Color research and application》2015,40(6):585-591
Data is presented on the colour and spectral reflectances of stool samples from healthy young infants (mean age 6 days). The range of spectral reflectances is well described by a pigment mixture model with three components—a pale component corresponding to partially digested milk fats, a yellow component corresponding to bilirubin breakdown products, and a dark component corresponding to meconium and bilirubin. Most stools were tan, beige or olive but white, grey and light grey were also observed. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 585–591, 2015 相似文献
13.
Yan Liu James Shigley Emmanuel Fritsch Scott Hemphill 《Color research and application》1995,20(4):245-250
The blue-to-purple color appearance change observed in some rare specimens of the gemstone tanzanite between daylight and incandescent light is contrary to the hue-angle change calculated between CIE illuminants D65 and A in CIELAB color space. This abnormal calculated hue-angle change for tanzanite can be corrected by using the spectral sensitivity functions of the three kinds of cone photoreceptors to directly calculate color. This study suggests that the cone spectral sensitivity functions are more fundamental in color calculations than the CIE color-matching functions. 相似文献
14.
15.
M. Melgosa M. M. Prez E. Hita M. J. Moyano J. Alba F. J. Heredia 《Journal of the American Oil Chemists' Society》2000,77(10):1093-1100
Twenty experienced observers with nondefective color vision judged 27 virgin olive oil samples within an acceptable color range, using the bromthymol blue (BTB) method, under controlled observation conditions (daylight source with a correlated color temperature of 6500 K, and standard gray back-ground). On the average, 44.8% of the observers agreed in their selections of the BTB standard solution matching a given oil sample, and this percentage increased to 88.2% considering ±one step in the two dimensions (pH and concentration) of the BTB scale. On the average, the lowest color difference between oil samples and available BTB solutions was 6.6 Commission Internationale de l'éclairage 1976-(L*a*b*) (CIELAB) units, but this color difference was approximately two times greater for the color difference between oil samples and BTB solutions selected by our observers. The colors of the BTB standard solutions in the CIELAB space are not uniformly distributed, and thus one step in pH or concentration is equivalent to CIELAB color differences varying in a wide range (1.7–13.5 and 1.7–26.3 CIELAB units, respectively). From these values, indicating low precision, accuracy, and uniformity, some suggestions are made for future improvements of the current BTB method. 相似文献
16.
Harry H. Tigelaar 《时间序列分析杂志》1985,6(2):109-115
Abstract. In this paper we give conditions for identifiability of the parameters of a linear system that is disturbed by moving average noise, where the inputs are generated by a multivariate ARMA-process. The identifiability is based on finite samples from in-and output. 相似文献
17.
设计了基于电能高精度计量芯片的快速三相谐波分析仪。分析仪采用嵌入式结构,使用安全管理平台技术,以STM32处理器为核心,通过地址/数据总线搭载专用电能计量芯片ATT7022D。分析仪利用硬件ADC缓存功能实现电量数据的快速采集;STM32处理器内置专用的FFT算法进行谐波分析,其产生的频谱泄漏和栅栏效应则采用拉格朗日三次插值算法进行了修正。应用结果表明:分析仪测量精度高、处理速度快、可靠性高。 相似文献
18.
提出一种基于喷墨式平板打印机的个性化双金属温度计刻度盘标定方法及其绘图软件。根据校准温度值的指针偏转角度,利用拉格朗日插值法对其他温度对应的偏转角度进行拟合,然后利用Matlab语言设计刻度盘绘图软件。应用结果表明:经过拉格朗日插值法拟合的刻度盘具有较高的温度测量准确度,刻度盘绘图软件能够同时对多个盘面信息进行录入、编辑和精确打印。 相似文献
19.
Galina V. Paramei Yulia A. Griber Dimitris Mylonas 《Color research and application》2018,43(3):358-374
Russian color naming was explored in a web‐based experiment. The purpose was 3‐fold: to examine (1) CIELAB coordinates of centroids for 12 Russian basic color terms (BCTs), including 2 Russian terms for “blue”, sinij “dark blue”, and goluboj “light blue”, and compare these with coordinates for the 11 English BCTs obtained in earlier studies; (2) frequent nonBCTs; and (3) gender differences in color naming. Native Russian speakers participated in the experiment using an unconstrained color‐naming method. Each participant named 20 colors, selected from 600 colors densely sampling the Munsell Color Solid. Color names and response times of typing onset were registered. Several deviations between centroids of the Russian and English BCTs were found. The 2 “Russian blues”, as expected, divided the BLUE area along the lightness dimension; their centroids deviated from a centroid of English blue. Further minor departures were found between centroids of Russian and English counterparts of “brown” and “red”. The Russian color inventory confirmed the linguistic refinement of the PURPLE area, with high frequencies of nonBCTs. In addition, Russian speakers revealed elaborated naming strategies and use of a rich inventory of nonBCTs. Elicitation frequencies of the 12 BCTs were comparable for both genders; however, linguistic segmentation of color space, employing a synthetic observer, revealed gender differences in naming colors, with more refined naming of the “warm” colors from females. We conclude that, along with universal perceptual factors, that govern categorical partition of color space, Russian speakers’ color naming reflects language‐specific factors, supporting the weak relativity hypothesis. 相似文献
20.
提出了一种新的约束三次样条插值算法,该算法把样条插值的光滑性和线性插值的优越性有机结合在一起,克服越界现象,得到的插值函数更能反映实际问题的特性。 相似文献