ISSN:0361-2317    

DOI:10.1002/col.5080070402

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

年代:1982

数据来源: WILEY

摘要:

AbstractThree attributes of color appearance of sixteen samples illuminated by various light sources were estimated directly by two observers. The results are plotted on a subjective chroma diagram, with which the psychometricchroma diagrams calculated from the CIELUV and CIELAB spaces are compared. The comparison and numerical evaluations show that the CIELAB space is much better than the CIELUV andU* V* W*spaces in simulating surface‐color appearance under various illuminants. Substitution of the CIELAB space for theU* V* W*space used in the CIE method of color‐rendering specification is propo

ISSN:0361-2317    

DOI:10.1002/col.5080070403

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

年代:1982

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080070404

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

年代:1982

数据来源: WILEY

摘要:

AbstractRecently, several methods for correcting for chromatic adaptation have been proposed by Richter, Bartleson, Nayatani, and others. Psychometric‐chroma coordinates are calculated according to these methods for surface colors illuminated by various light sources, and are compared with the results of subjective experiments on color appearance. For this purpose some experiments using saturated color illuminants are included. The nonlinear transformation proposed by Nayatani and others applied in CIELAB space correlates best with the subjective appearance of surface color

ISSN:0361-2317    

DOI:10.1002/col.5080070405

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

年代:1982

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080070406

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

年代:1982

数据来源: WILEY

ISSN:0361-2317    

DOI:10.1002/col.5080070407

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe daytime color of retroreflective materials is a mixture of sensations caused by diffusely reflected light plus a small amount of retroreflected light, the exact mixture depending on the illumination geometry and the goniophotometric characteristics of the material. The most nearly comparable results of color measurement can be obtained with instruments having 45°/0° geometry instead of sphere geometry. Spectrophotometers or colorimeters can be used. The calibration of these instruments is discussed. Most specifications for the daytime color of retroreflective materials call for the use of CIE standard illuminantD65. However, one can use colorimeters designed to give color coordinates for illuminantCprovided that color standards calibrated forD65are use

ISSN:0361-2317    

DOI:10.1002/col.5080070408

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

年代:1982

数据来源: WILEY

摘要:

AbstractAs one of its major efforts during the past three years, the Retroreflectance Subcommittee of CIE Technical Committee 2.3 has defined a system of geometrical coordinates to be used for working with retroreflection. This coordinate system, along with an associated set of defined terms, is intended to provide a common language for describing and specifying the performance of retroreflecting materials and objects.

ISSN:0361-2317    

DOI:10.1002/col.5080070409

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

年代:1982

数据来源: WILEY

摘要:

AbstractTwo organizations, the International Commission on Illumination (CIE) and the American Society for Testing and Materials (ASTM), have recently agreed on the definition of the coefficient of retroreflection. This coefficient is determined using CIE Standard Illuminant A and a receptor responsivity matching that of the CIE 1931 Standard Observer. Although this coefficient is practical for day‐to‐day measurements, a more general quantity is needed to study new materials, differing vehicle illumination, and the effects of human responses ranging from scotopic to photopic, as well as anomalous color vision. A CIE technical report, soon to be published, suggests that a new quantity, the spectral coefficient of retroreflection, be used to aid in studying these properties. The measurement of the spectral coefficient of retroreflection over the visible spectrum is performed by spectroradiometric techniques. This property of the retroreflector is independent of the spectral power distribution of the illuminant and the responsivity of the receptor. The retroreflector may now be studied mathematically, applying other illuminants and human visual responses. A useful byproduct of the determination of the spectral coefficient of the retroreflection is the ease with which the nighttime color can be determined. The article concludes with various examp

ISSN:0361-2317    

DOI:10.1002/col.5080070410

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

年代:1982

数据来源: WILEY

摘要:

AbstractA photometric range for measurement of retroreflectance using a computer‐controlled four‐axis goniometer for positioning the test specimen and a computer‐controlled observation‐angle drive is described. The four‐axis goniometer allows for positioning of all types of retroreflectors in the CIE (α, β1, β2, ϵ) geometric system and has the flexibility to provide direct angular positioning in other geometric systems. The observation‐angle drive allows accurate alignment of the observation angle at variable test distances. Included is a description of the calibration methods used to insure photometric accuracy and stability for the duration of the measurement. The control of both the photometric and geometric systems uses peripheral devices interfaced to a central computer. Computer programs are outlined that provide output in terms of selected sets of angles at which measurements are required to verify performance in user specifications. Also described are graphic outputs of retroreflectance versus angle which are used to characterize the intrinsic performance of retrorefle

ISSN:0361-2317    

DOI:10.1002/col.5080070411

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

年代:1982

数据来源: WILEY