ISSN:0361-2317    

DOI:10.1002/col.5080140102

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

年代:1989

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080140103

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

年代:1989

数据来源: WILEY

摘要:

AbstractLast August I devoted one of these columns to the subject of defective color vision and suggested that it would be very instructive to hear from persons who have a color‐vision defect about the difficulties they experience and also from parents who have a son or daughter with a color defect about the difficulties that arise at school.It transpired that Professor R. J. Fletcher, the present Chairman of our British Colour Group, had been thinking along the same lines, and this led him to organise a very interesting meeting of the Group at The City University in London on 2nd March, 1988, when several speakers described the nature of their color defects and how they managed to cope with them. I seized the opportunity to enroll two of the speakers to contribute to this column, one of them, Mrs. L. Newport, being a school teacher. She herself has normal color vision but her 15‐year‐old son Philip has a protan defect. She is, therefore, well placed to advise both school teachers and parents on how to assist children with color defects.The other contributor, Mr. S. C. Abery, is an optometrist; here he uses his knowledge as a visual specialist to describe the problems he has had as a result of his color defect, which was first established when he was four. His account begins.I hope these two contributions will set teachers and parents talking about color and working out ways of easing the lot of color‐defective youngsters. Our journal, too, can play its part by publicising the problem. I once suggested2that it might be no bad thing if a Dalton Society were established at which those with color defects could compare notes and perhaps make recommendations on alternative methods of identification in place of color codes. How about it, Mr. Abery?Finally, I must mention that there is a very active International Research Group on Colour Vision Deficiencies which meets every two years, and the secretary of the Group, Dr. Verriest, publishes a Newsletter under the title Dalt

ISSN:0361-2317    

DOI:10.1002/col.5080140104

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

年代:1989

数据来源: WILEY

摘要:

AbstractA procedure is described whereby the subset of Munsell colors of maximum chroma, which has been used by anthropologists to study color naming since Berlin and Kay in 1969, can be specified in theL,j,gcoordinate system developed more recently by the Uniform Color Scales Committee of the Optical Society of America. The latter permits a meaningful specification of the centroid location of colors named by each basic term. The procedure is validated by comparing centroids obtained from six subjects who named samples of both the Munsell and OSA sets, and its usefulness is illustrated by comparing data from a four‐year old who named only OSA samples and four‐ and two‐year‐olds who named only Munsell

ISSN:0361-2317    

DOI:10.1002/col.5080140105

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

年代:1989

数据来源: WILEY

摘要:

AbstractThis article extends matrix‐Roperations, developed by Cohen and Kappauf in 1982 and 1985 and by Cohen in 1988, to create generalized metameric object color stimuli, here termed multiple metamers, that remain metameric with respect to several different illuminants. As discussed in prior literature, matrix‐Roperations resolve any radiometric function (specifying a color stimulus) into a fundamental color stimulus and a residual or metameric black, as hypothesized by Gunter Wyszecki in 1953. The fundamental is sensed by the visual system while the residual is ignored. Metameric color stimuli comprise the same fundamental but different residuals. Thus, matrix‐Roperations easily construct metameric suites under an equal‐energy source or under any other illuminant whose physical specification is incorporated into the radiometric function of the color stimulus entering the visual system. In the present article, matrix‐Roperations are extended to create metameric stimuli that theoretically remain metameric with respect to an arbitrary number of sequential illuminants. While the stimuli remain metamers under different illuminants, the color sensation evoked with respect to one illuminant is generally different from the color sensation evoked with respect to another illuminant. Examples demonstrate multiple metamers with respect to CIE standard illuminants A and C and with respect to four artificial illuminants. In principle, extended matrix‐Roperations create multiple metamers with respect to different observers, or with respect to any combination of observers and

ISSN:0361-2317    

DOI:10.1002/col.5080140106

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

年代:1989

数据来源: WILEY

摘要:

AbstractBecause of the large number of stimulus configurations that may be displayed on a computer controlled color monitor, direct measurement of the relation between the digital input values to the frame buffer and the output of the monitor is not possible. To calibrate a monitor, it is necessary to make assumptions about the monitor's performance. These assumptions allow the monitor's output for any set of input values to be predicted from the input values and the results of a feasible number of calibration measurements. This article describes a set of assumptions that are sufficient to render the problem of monitor calibration tractable. These are the assumptions of phosphor constancy, phosphor independence, spatial independence, and the single scale factor assumption. If these assumptions hold, a monitor may be calibrated by measurements of the phosphor spectral power distributions, measurements of the phosphor input‐output relations, and measurements of the spatial scale factor at a number of locations. Violations of these assumptions limit the accuracy of calibration. The results of measurements that test the validity of these assumptions for a Barco 5351 monitor are presente

ISSN:0361-2317    

DOI:10.1002/col.5080140107

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

年代:1989

数据来源: WILEY

摘要:

AbstractMany diseases involve the introduction into the body of highly specific foreign substances (antigens) to which the body responds by producing complementary antibodies. A test method has been developed whereby several different antigens can be detected simultaneously. One drop of fluid (e.g., blood serum, urine, saliva, etc.) from the patient is mixed with one drop of reagent on a card. Within two minutes a colour change takes place, each colour developed being diagnostic of a particular antigen. This paper describes the test and shows how colorimetric methods were used to optimise its performance, standardise the materials used, and determine the requirements for proposed further development.

ISSN:0361-2317    

DOI:10.1002/col.5080140108

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

年代:1989

数据来源: WILEY

摘要:

AbstractWhen a color differs from the reference, it is desirable to ascribe the difference to differences in the perceptual attributes of hue, chroma, and/or lightness through psychometric correlates of these attributes. To this end, the CIE has recommended the quantity ΔH* as a psychometric correlate of hue as defined by ΔH* = [(ΔE*)2‐ (ΔL*)2‐ (ΔC*)2]1/2, where the correlates correspond to either the 1976 CIELAB or CIELUV color spaces. Since ΔH* is defined as a “leftover,” this definition is valid only to the extent that ΔE* comprises exclusively ΔL*, ΔC*, and ΔH* and that ΔL*, ΔC*, and ΔH* are mutually independent compositionally, both psychophysically and psychometrically. It will be shown that as now defined ΔH* lacks psychometric independence of chroma and always leads to incorrect hue difference determination. Such a deficiency causes problems, especially in the halftone color printing industry, since it can suggest an incorrect adjustment for the hue of the inks. A revised definition herein of ΔH* provides a psychometric hue difference independent of chroma, valid for large and small psychometric color differences regardless of chroma. However, for small chromas, the seldom used metric ΔCmight be a better color difference metric than ΔH* because complex appearance effects make the perceptual discrimination of lightness, chroma, and hue components more difficu

ISSN:0361-2317    

DOI:10.1002/col.5080140109

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

年代:1989

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080140111

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

年代:1989

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080140112

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

年代:1989

数据来源: WILEY