ISSN:0361-2317    

DOI:10.1002/col.5080170502

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

年代:1992

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080170503

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

年代:1992

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080170504

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe ruby reds and the strong blues of the stained glass windows of Romanesque and Gothic cathedrals are some of the most magnificent pieces of craftsmanship mankind has produced. According to our knowledge, no colorimetric attempt has been made to understand the visual impression produced by them. Modern colour‐appearance models permit the description of the colour impression produced by chromatic stimuli under changing adaptation conditions. In the present article, an attempt is made to model the visual situation and to use the colour‐appearance model developed by Nayatani and co‐workers for colorimetrically describing the observed effects. In model experiments, “extra brightness” was found when changing the direction of view from the dark surrounding to the well lit stained glass window. Calculations based on the Nayatani model yielded similar extra brightness and extra colourfulness, in good agreement with visual obs

ISSN:0361-2317    

DOI:10.1002/col.5080170505

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

年代:1992

数据来源: WILEY

摘要:

AbstractWe compare several computational schemes that can be used for the simulation of object colors under changing illuminant conditions on electronic displays. These schemes differ in the assumptions that are made concerning illuminant invariant quantities, and the amount of a priori information that is required. This latter feature is especially important for computer graphics applications and theoretical color constancy research because in many instances information about illuminant and object characteristics is minimal. A large set of tristimulus values of Munsell papers, as defined under CIE Standard Illuminant C, served as input data. Next, illuminant invariant quantities were obtained for each computational scheme that were used to predict x, y chromaticity coordinates and relative luminosity Y under nine different phases of daylight, varying from 4000 K to 20000 K. It was found that the differences between so‐called reflectance models on the one hand, and theoretically less accurate tristimulus ratio models on the other, are small and in most cases within three MacAdam units of color difference ≈1 J

ISSN:0361-2317    

DOI:10.1002/col.5080170506

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe problem of color correction for changes in illumination is briefly reviewed. A new method using the spectral reflectance distribution in the image is introduced and compared to a white‐point mapping method. The new method is based on principal component analysis and thus is dependent upon the characteristics of the images that are to be viewed. These two methods are compared using chromaticity plots and the CIE L*a*b* ΔE measurement, for test samples which include color copiers, thermal writers, ink‐jet printers, and lithogr

ISSN:0361-2317    

DOI:10.1002/col.5080170507

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

年代:1992

数据来源: WILEY

摘要:

AbstractColour electronic displays are being used increasingly for information presentation in a wide range of applications. A prerequisite to the effective use of colour coding is that the colours be discriminable under all of the conditions in which the display will be used. For applications such as radar, medical imaging, or electronic charts, different coloured areas may be juxtaposed and coloured symbols superimposed on a multicoloured background. Under such conditions, the colours in the display may affect the appearance and discriminability of each other. the present article examines the extent to which a set of colours that is clearly distinguishable when presented against a uniform background might be confused when the members are presented against differently coloured backgrounds. This was achieved by measuring the range of chromaticities, presented against a grey background, that would be confused with each of the test colours when they were presented against different chromatic surrounds. the findings were used to derive the characteristics of sets of colours that should be discriminable in a complex display.

ISSN:0361-2317    

DOI:10.1002/col.5080170508

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe range of interference colors that become apparent when thin layers of titanium oxide are electrolytically produced on the surface of the metal are described in terms of simple visual assessments, Munsell designations, and CIELAB color space values. the observed colors change to some extent with the angle of illumination and viewing. the form of the visible reflectance spectra of the surfaces also depends on the optical configuration of the spectrophotometer. Measurements made with an integrating sphere with a 0°/8° geometry provide CIELAB values that are more representative of the appearance of the colors than the values calculated from spectra obtained by 0°/45° diffuse reflecta

ISSN:0361-2317    

DOI:10.1002/col.5080170509

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

年代:1992

数据来源: WILEY

摘要:

AbstractHigh‐intensity‐discharge (HID) headlamps, in comparison to tungsten–halogen headlamps, emit proportionally less energy in the long‐wavelength end of the visible spectrum—precisely in the region where retroreflective red stop signs are most reflective. A likely consequence of the use of HID headlamps is a colorimetric shift of stop signs. This study was designed to examine the consequences of colorimetric shifts of red sign materials in different colorimetric directions. Subjects were shown individual small color samples under controlled lighting conditions. Their task was to indicate, on each trial, whether the sample color was acceptable for stop signs. At the end of each experimental session, subjects were asked to select a single most appropriate color for stop signs from among 16 simultaneously presented color samples. There are two main findings. First, there is an overwhelming agreement among observers concerning the most appropriate red color for stop signs out of the 16 colors presented. Second, observers were relatively sensitive to hue shifts towards orange, while relatively insensitive to saturation shifts towards pink. Consequently, designers of HID headlamps should try to minimize the extent of colorimetric shifts of red sign materials towar

ISSN:0361-2317    

DOI:10.1002/col.5080170510

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

年代:1992

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080170511

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

年代:1992

数据来源: WILEY