ISSN:0361-2317    

DOI:10.1002/col.5080170402

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.5080170403

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.5080170404

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe present article describes a color classification method that partitions a color image into a set of uniform color regions. The input image data are first mapped from device coordinates into the CIE L*a*b* color space, an approximately uniform perceptual color space. Colors used to represent a natural color image are classified by means of cluster detection in the uniform color space. The basic process of color classification is based on histogram analysis to detect color clusters sequentially. The principal components of a color distribution are extracted for effective discrimination of clusters. We present an algorithm for sequential detection of color clusters in the uniform color space, and the related algorithms for region processing and color computation. The performance of the method is discussed in an experiment using three kinds of natural color images.

ISSN:0361-2317    

DOI:10.1002/col.5080170405

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe instrument used to gather the data of this article, a bright split‐field visual colorimeter coupled by quartz light pipe to a spectroradiometer, generated many pairs of lights visually‐matching to one of six normal human observers. an accurate absolute spectral power distribution (SPD) was obtained for every such viewed light. Three disparate primary‐sets were used. Large errors in chromaticity and brightness (represented by luminance), computed by the 1964 CIE Standard Observer, were found to pervade the results. Problems are introduced by the use of maximum‐saturation CMFs, by transformation of primaries, by the structure of the CIE chromaticity diagram, and by measurement inaccuracies of the far past. In Part III, alternative derivations of weighting functions, multiplied against the absolute SPDs of the visually‐matching lights to obtain what are called tristimulus values, are shown to reduce errors in computed chromaticity. an alternative brightness function, of complexity commensurate with that of the three‐input normal human visual system, is shown to correlate considerably better to perceived brightness of white and colored lights than does computed luminance. an alternative chromaticity diagram is constructed of two chromatic terms of the brightness function, as a constant‐perceived‐brightness plane (which conventional diagrams are not), and avoids problems inherent in the conve

ISSN:0361-2317    

DOI:10.1002/col.5080170406

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe Colorcurve System is first and foremost a system for color communication. It provides a direct means of communication between spec (fiers or creators of color and the manufacturer of colored products. It is a combination of a visual and numerical system. The system is made up of four main elements: (1) Aim points in CIE L*a*h* color space; (2) Physical representation of the aim points; (3) Data tables and numerical descriptions of the aim points; and (4) Computational methods andlor computer software. A simple notation system that can be easily understood by both creative people and industrial technologists was developed. The numerical description of each aim point can aid manufacturers in getting acceptable color matches in a variety of materials because it fits in with the procedures used for computer color matching. © 1992 John Wiley&Sons, Inc

ISSN:0361-2317    

DOI:10.1002/col.5080170407

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

年代:1992

数据来源: WILEY

摘要:

AbstractNCS (C/1931) and DIN (C/1931 and D65/1964) notations of the 558 OSA‐UCS atlas samples are presented in two tables. One table provides the NCS and DIN notations for the 424 regular samples; the other for the 134 near‐neutral (half‐step) sa

ISSN:0361-2317    

DOI:10.1002/col.5080170408

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

年代:1992

数据来源: WILEY

摘要:

AbstractFilm nonuniformities cause many problems for the coating scientist. One area of coating film performance that they impact directly is optical properties. Measurements and predictions of film optical performance are all made assuming uniform film thickness. Incomplete leveling and other film application problems often yield nonuniform films with significant film thickness fluctuations. These film thickness imperfections can be modeled by a sine wave thickness fluctuation, and this fluctuation can be used to estimate the effects of nonuniformity in thickness on optical properties. This has been done using both approximate equations for scattering, transmission, and reflectance in films (zero absorption) and for the Kubelka‐Munk equations including absorption. the effects of average film thickness and amplitude of fluctuation on measured S, R, and T values are predicted numerically for several cases of [K, S] pairs consistent with wavelength independent situations (white or similar films) over black substrates, and then the calculations are used to consider colored films [considering δE(L*a*b*)]over black substrates. Film thickness fluctuations are shown to have considerable impact on film optical properties, especially in thin highly scattering films. Examples of the types of predictions that can be made are given; how the results depend on the coating optical parameters is also sho

ISSN:0361-2317    

DOI:10.1002/col.5080170409

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.5080170410

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.5080170412

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

年代:1992

数据来源: WILEY