ISSN:0361-2317    

DOI:10.1002/col.5080050101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080050102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe Munsell Color System, the color‐appearance system most widely used, has been constructed primarily on the basis of local perceptual uniformity. However, when it is used as a criteron for a uniform chromaticity scale, its global structure is important as well, and this structure is examined in three ways. First, the coordinates H, V, C are shown to function as a conceptual framework in identifying colors. Second, a summary of 12 studies by multidimensional scaling methods based on large color differences is given. It shows that the main part of the Munsell space is approximately Euclidean. Third, a new method based on estimation of principal hue components in each color, 120 in an experiment, yields the same result. Chromatic response functions as in opponent‐color theories are obtained with object colors by this method. In all the results with Japanese observers, 5PB and 5B appear to be too close and both deviate toward 5G compared with the Munsell notation. Whether the finding is due to the observers is discus

ISSN:0361-2317    

DOI:10.1002/col.5080050103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA new method of measuring chromatic discrimination steps is described where observers must indicate in which direction a change has occurred, as well as the fact of its occurrence. This procedure seems to stabilize the subject's criterion of difference and yields step sizes more akin to those of Wright's “dashes” than MacAdam's ellipses. Tests have been made along two critical dimensions of variation: (1) the tritan axis, where discriminations depend initially only on variations in blue‐cone (B) excitation and (2) the red‐green axis, where discriminations depend on the substitution of red‐cone (R) excitation for that of green cones (G), or vice versa. Discriminations dependent on blue cones are affected by the level of B‐cone excitation but are independent of R/G. After individual differences are taken into account by a simple scaling factor, an equation of the form ΔB/ B + Bo= K accounts well for the data. Blue‐cone discrimination is found to be independent of the ratio of red‐to‐green‐cone excitation, with an optimal Weber fraction of about 18%. Discriminations dependent on the exchange of red‐and green‐cone excitation yield an optimal Weber fraction of about 2%. This ratio is increased, though not greatly, by an imbalance of the red‐green ratio relative to a neutral condition, and by increasing the level of blue‐cone excitation. At 120 td, the ratio between a MacAdam step and ours is approxim

ISSN:0361-2317    

DOI:10.1002/col.5080050104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080050105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe recommendations of the International Commission on Illumination (CIE) on the CIELUV 1976 and CIELAB 1976 color spaces are discussed. A cube‐root chromaticity diagram (a',b') for CIELAB 1976 is added. A slightly modified cube‐root chromaticity diagram (A',B') is proposed which takes care of the CIE corrections (1978) for saturated yellow and red colors in CIELAB 1976 color space. Important advantages of the corresponding cube‐root color space labeled LABHNU 1977 are shown and compared to the CIELUV 1976 and CIELAB 1976 color spaces. Chromatic adaptation can be described approximately as an equal (cube‐root) chromaticity shift for all test colors defined by the two chromaticities of the adaptation illuminants. These properties are discussed and compared to our own chromatic‐adaptation data and data published by Bartleson (1978). Color‐appearance attributes and differences are studied for CIE standard illuminants D65and A. The Munsell data and OSA data and the main properties of different experiments of Evans and Swenholt (1968) and Pointer (1974) lead to the LABHNU 1977 color space which is evaluated for chromatic adaptation to different illuminants and is compared to the CIELAB 1976 and CIELUV 1976 c

ISSN:0361-2317    

DOI:10.1002/col.5080050106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080050108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractEleven color‐difference formulae were tested for medium and large color differences in a psychophysical experiment on color scaling. A preliminary report has been published and one more formula has been added since then. A third experiment is included in this report dealing with variations of the field size and background. The results were tested statistically for conformance to three different types of mathematical law (linear, exponential, and potential) and with a few exceptions, linear approximation showed the higher regression coefficient. For color differences as large as 17 ± 11 CIELAB units, this experiment suggests that the CIELAB formula is a good recommendation, but it is no better than the new proposal of Richter or the well‐known cube root and Adams‐Nickerson fo

ISSN:0361-2317    

DOI:10.1002/col.5080050109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractProblems relating to the measurement and description of color of wines are discussed, with wines providing an example of problems of volume color specification in general. The limitations of conventional directional spectrophotometric transmittance measurements are considered for colloidal, minimally light‐scattering systems, where errors due to light lost through scatter can have profound consequences, particularly at shorter wavelengths. An alternative approach, referred to as transreflectometry, avoids the errors attributable to the directional geometry of conventional spectrophotometers. A review of its application to the colorimetry of wines considers three cases with different requirements to be met and different questions to be answered, from meeting strigent Federal Regulations in the case of very light white wines, to blending red and rosé wines to predetermined color requirements, to studying the kinetics of pigment degradation and colored polymer formation in red wines under controlled storage conditions. These studies demonstrate the versatility of a simple methodological approach which provides information relating to visually perceived color and at the same time to chemical and physical properties of the syste

ISSN:0361-2317    

DOI:10.1002/col.5080050110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080050111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY