ISSN:0361-2317    

DOI:10.1002/col.5080160302

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

年代:1991

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080160303

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

年代:1991

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080160304

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

年代:1991

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080160305

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

年代:1991

数据来源: WILEY

摘要:

AbstractTo provide a more realistic balance between the relative contributions from cones and rods to the achromatic signal, at various levels of adaptation, revisions have been made to a previously published model of colour vision. Visual areas denoted as the adapting field, the surround, the background, and the proximal field have also been defined. Several minor changes have also been made to make the model more convenient to use. The steps required in using the model are described, and worked examples are included for both related and unrelated colours. For related colours, the differences between the original and revised models are fairly small in the results obtained for samples viewed on grey, or typical average‐scene, backgrounds, at normal photopic levels of illumination, except for lightness and chroma; but for light and dark backgrounds, more wide‐spread changes occur. For unrelated colours, the revised model includes the Bezold‐Brücke dependence of hue on luminance. The predictions given by the model are compared to physiological and psychophysical experimenta

ISSN:0361-2317    

DOI:10.1002/col.5080160306

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe work described here forms part of a research project entitled Predictive Perceptual Colour Models. The aim of this project is to develop a colour appearance model capable of predicting changes of colour appearance under various different viewing conditions. This will provide industry with a quantitative measure for assessing the quality of colour reproduction and enable more rapid and accurate proofing simulations in the graphic art industry. A large‐scale experiment has been carried out in which colour appearance was assessed under a wide range of viewing conditions. The parameters studied were (1) D65, D50, white fluorescent, and tungsten light sources, (2) luminance levels of about 40 and 240 cd/m2, (3) five background conditions: white, grey, black, grey with white border, and grey with black border, and (4) two media: luminous colours (displayed on a high‐resolution colour monitor) and nonluminous colours (presented in a viewing cabinet). Each colour was assessed by a panel of six or seven observers using a magnitude estimation method. In total, 43,332 estimations were made, and these form the LUTCHI Colour Appearance Data. Data analysis has been carried out to examine the reliability of the experimental results and to understand the effects of the various viewing parameters studied. (Part II of this article describes how the LUTCHI Colour Appearance Data has been used to test the performance of various colour spaces and mod

ISSN:0361-2317    

DOI:10.1002/col.5080160307

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe acquisition of the LUTCHI Colour Appearance Data has been described in Part I of this article. Having obtained the data, they were used to test the accuracy of prediction for various colour spaces and models. The results clearly indicate that Hunt's 91 model gives the best fit to the visual results of all the models studied. Hunt's 91 has been further refined to improve the fit to the colourfulness results, and this refined model has been designated Hunt‐ACAM (ACAM being the Alvey Colour Appearance Model). The error of prediction from Hunt‐ACAM is close to the typical error that is seen to occur between individuals' results and the mean visual results. This performance is considered to be very satisfactory, and the model is therefore believed to provide a reasonably accurate way of evaluating colour fidelity for various colour reproduction systems. Various chromatic‐adaptation transformations were also compared with three sets of corresponding chromaticities derived from the results of experiments conducted under four conditions of chromatic adaptation. The results are in reasonable agreement with those obtained by Helson et al. [Illum. Eng.47, 221–233 (1952)] and Lam and Rigg [Ph.D. thesis, University of Bradford (1985)]. All results indicate that the Bradford and Hunt‐ACAM transformations perform the best and the second best, respectively, of all the selected formulae. The current CIE recommendation does not perform as well as

ISSN:0361-2317    

DOI:10.1002/col.5080160308

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

年代:1991

数据来源: WILEY

摘要:

AbstractChevreul wished to represent in his color system every modification of color, including not only the modifications we observe from pigment mixtures but also those modifications in color that we observe in nature. The latter include the various gradations of light and shade on the surface color of objects which light enables us to perceive. A review and clarification of his color system reveals a logical correlation between these phenomena and the various scales in his color system. Studying these scales and understanding the concepts they represent can be very helpful to painters who wish to represent in their paintings objects in space and light in a naturalistic manner.

ISSN:0361-2317    

DOI:10.1002/col.5080160309

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

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper describes a system of photometry designed to make no unjustifiable assumptions, and to have a strong visual linkage. It spans the photopic, mesopic, and scotopic regions and is based on brightness matching a 10‐degree field, centrally fixated. An intensive investigation was made on the trichromator at the National Physical Laboratory, Great Britain, and an extensive one, using a greater number of observers, on the trichromator at the National Research Council, Canada. A bipartite field allowed equal brightness settings of the aperture colour by each of nine observers. The stimuli tested were both spectral and nonspectral and the data were used to derive formulae which a user could employ. From inserting conventional photometric quantities of a stimulus, which might for example be a light source, the user can obtain its corresponding photometric value whether it be photopic, mesopic, or scotopi

ISSN:0361-2317    

DOI:10.1002/col.5080160310

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

年代:1991

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080160311

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

年代:1991

数据来源: WILEY