Set theoretic estimation for problems in subtractive color

The use of linear algebra and set theoretic estimation for problems in color science and imaging is reviewed. Through a product‐space formalism, the powerful projections onto convex sets (POCS) algorithm is extended to subtractive color systems satisfying convex constraints in the density domain. Several convex sets are defined, which are useful in color science and imaging, and projections onto these sets are presented. The usefulness of the new methods is demonstrated by applying them to three practical problems: (1) model‐based scanner calibration, (2) design of color scanning filters that are color mixture curves, and (3) colorant formulation. © 2000 John Wiley & Sons, Inc. Col Res Appl, 25, 333–348, 2000     

Applications of vectorial color

A companion article introduced a set of orthonormal opponent color matching functions (CMFs). That “orthonormal basis” is an expedient for plotting lights in Cohen's logical color space. Indeed, graphing the new CMFs together (as a parametric plot) gives Cohen's invariant locus of unit monochromats (LUM). In this article, the functions and related vector methods are applied to fundamental problems. In signal transmission and propagation‐of‐errors work, it is desirable to describe stimuli by decorrelated components. The orthonormal CMFs inherently do this, and an example is worked out using a large set of color chips. Starting with the orthonormal functions, related functions, such as cone sensitivities, are graphed as directions in color space, showing their intrinsic relationships. Building on work of Tominaga et al., vectorial plots are related to the problem of guessing the illuminant, a step toward a constancy method. The issue of color rendering is clarified when the vectorial compositions of test and reference lights are graphed. A single graph shows the constraint that the total vectors are the same, but also shows the differences in colorimetric terms. Since the LUM summarizes a trichromatic system by a three‐dimensional graph, dichromatic observers can be represented by 2‐D graphs, revealing details in a consistent way. The “fit first method” compares camera with human, applying the Maxwell‐Ives criterion in graphical detail. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011.     

A data set for color research

We present an extensive data set for color research that has been made available online ( www.cs. sfu.ca/～colour/data) . The data are especially germane to research into computational color constancy, but we have also aimed to make the data as general as possible, and we anticipate a wide range of benefits to research into computational color science and computer vision. Because data are useful only in context, we provide the details of the collection process, including the camera characterization, and the data used to determine that characterization. The most significant part of the data is 743 images of scenes taken under a carefully chosen set of 11 illuminants. The data set also has several standardized sets of spectra for synthetic data experiments, including some data for fluorescent surfaces. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 147–151, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10049     

Applications of electron microscopy methods to catalyst problems

The importance of electron microscopy techniques in tackling catalyst problems is considered. In particular the use of the imaging and spectroscopy facilities of the scanning transmission electron microscope is discussed and illustrated with some recent studies of catalytic materials. The advantages of using non-penetrating incident beams in electron-energy-loss spectroscopy, and glancing incidence microscopy, are especially highlighted.Paper presented at the Royal Society-U.S.S.R. Academy of Sciences Workshop, Christ Church, Oxford, April 8–11, 1989.     

Processing methods to preserve quality and color of cottonseed flakes

Hull-free cottonseed flakes were prepared for direct solvent extraction by two passes through a pilot plant size, hot air drier set at 200 F. Moisture content was reduced to 6.5% without evidence of gossypol binding. Improved drainage characteristics resulted in better extraction. Glanded and glandless flakes which had been extracted and partially desolventized at low temperatures were heated indirectly in a batch desolventizer under vacuum to temperatures above the point of steam condensation and solvent stripped with superheated steam. Resulting available lysine and protein solubility values on the meals and flours were desirably high. The desolventization was accomplished without significant color darkening. Operated by the Texas Engineering Experiment Station for the Cotton Research Committee of Texas.     

Survey of color order systems

Important modern color order systems accompanied by physical exemplifications (atlases) are surveyed; one of great historical interest, though not currently available, is included. The systems covered include the Munsell, Natural Color, OSA-UCS, DIN, Coloroid, and Ostwald systems. Their history, guiding principles, variables, and relation to the CIE system are described. Some of the interrelationships among the systems are then considered, specifically those between the Munsell system and the Natural Color and OSA-UCS systems. Implications for the consideration of international standard color order systems are mentioned.     

Applications of differential scanning calorimetry to photocurable polymer systems

Modification of a standard differential scanning calorimeter to allow irradiation of the sample material with ultraviolet light allows one to follow the course of polymerization of photocurable polymer systems. The rate and heat of polymerization are readily determined by this technique which gives it a number of very useful applications. As a quality control tool, one can use the heat of polymerization to monitor the number of reactive sites present in the prepolymer thus achieving a degree of control on the ultimate properties of the cured film. Similarly, analysis of a cured film will indicate the presence of any uncured material, thus allowing one to adjust curing conditions accordingly. The technique has numerous other applications in the study of photocurable resins, such as evaluation of initiator efficiencies, optimization of curing parameters (initiator concentration, lamp design), and the sensitivity of prepolymers to oxygen and wavelength.     

OSA uniform color scale samples: A unique set

The Optical Society of America, in early 1977, published a set of uniformly scaled coor samples based on specifications developed after long years of study by its Committee on Uniform Color Scales. The model for arranging and specifying the samples is based on an octahedral unit which consists of a cluster of 12 colors equally different from a central color and from each of its nearest neighbors. This space lattice, extended to accommodate all samples that can be produced within the gamut of present-day colorants, is described, together with the adopted system of notation. The lattice provides three sets of square grids and four sets of triangular grids that correspond to the seven pairs of parallel faces of a cuboctahedron. Horizontal, vertical, and oblique cleavage planes through the lattice are described and illustrated. The OSA-UCS set consists of 558 samples: 424 represent a regular 2-unit sampling of OSA-UCS committee space; 134 additional samples are provided in the much used, near-neutral, central-lightness region of color space. The set is unique because each sample in the regular set is represented in six different uniform color scales. These appear as linear arrays that pass in six different directions through each sample. The samples are intended for use by artists and designers as well as by scientists. With a relatively small number of samples, material is provided for constructing color scales and charts with colors uniformly spaced in six directions in any chosen part of color space. The OSA-UCS set provides a “storehouse of color-contrast information in efficient form.” It provides useful color research material such as has never before been available.     

Philosophy of perceptive color order systems

A color order system may arrange color perceptions, color stimuli, or material color samples according to certain rules. Material color systems have many practical applications but are different for different materials and different applications. Stimulus systems are useful in comparing instrumental measurements of transmitted or reflected radiation, but do not adequately describe the appearance of the color perceptions. In most perceptive color systems attributes like hue, saturation, and lightness (or their near correlates) describe three-dimensional color space. There are two main exceptions: the OSA–UCS system intended to be equidistant in all directions of color space, and the NCS, which is a Hering-type opponent system, based on six innate elementary colors with six corresponding attributes. In the NCS, hue and chromaticness, which in other systems are primary attributes, are derived from the elementary attributes.     

Physical exemplification of color order systems

Color order systems must be distinguished from colorant order systems and other systematic ways of relating colored objects. Abstract systems require definition of dimensions and scales. A concrete system is a collection of specimens exhibiting properties specified by the dimensions and scales of an abstract system. The accurate production of such specimens requires a complete written definition of the system, including the specification of all pertinent observing and measuring conditions. The choice of materials requires consideration of the spectral and geometric aspects of the optical nature, some aspects of the mechanical nature, stability, durability, availability, acceptability to users, and cost. The value of color standards depends on the precision and accuracy with which they are produced. Efficient production and long-term reproducibility depend on well-standardized methods of color measurement.     

Interobserver variability and color representation systems

A systematic method of analyzing the colorimetric behavior of a set of observers is proposed. The differences between each observer and a standard one are analyzed with different procedures in two color‐representation systems. It is apparent that these differences strongly depend on the color‐representation system in which they are analyzed. Results obtained in this work indicate that comparison between two observers should be carried out by applying an optimized operator. This operator minimizes the differences between the color‐representation systems associated with the observers that are compared. The proposed method should be applied when color‐matching properties of a set of observers, or when color matching obtained with different colorimetric instruments, are compared. © 2002 Wiley Periodicals, Inc. Col Res Appl, 28, 15–24, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.     

A comparison of five color order systems

Five color order systems (Munsell Renotations, Munsell Re‐renotations, OSA‐UCS, NCS, and Colorcurve) have been compared by optimizing the powers applied to individual opponent‐color functions. The results indicate general similarities in that powers applied to the red and green functions tend to be closer to 1, while those applied to the blue function and the yellow function are generally smaller. Specifically, there are many individual differences that make each system unique. The results inspire confidence in the veracity of the opponent‐color system methodology. © 2000 John Wiley & Sons, Inc. Col Res Appl, 25, 123–131, 2000     

建立科学评价方法以实现柴油机润滑油按质换油

润滑油的价格伴随原油价格上涨而节节攀升,润滑油的成本控制也就显得日益重要。对柴油机润滑油进行科学系统地管理是节省润滑费用、提高主机性能可靠性的有效方法。对现有的润滑油管理方式进行改善,建立科学的润滑油换油观念,借助润滑油检测机构进行油样化学分析和服务管理,实施按质换油,使柴油机润滑油得到最大限度的使用且保证主机无障碍运行,能取得最佳的润滑效益。     

Instrumental methods of monitoring color of vitreous enamels

Editor's Note: Currently, the color of silicate articles is mainly evaluated visually using standard specimens. The variability of this evaluation depends on individual judgement of the expert, the color atlas that is used, the lighting conditions, etc.An objective evaluation can only be obtained using instrumental methods. However, even when such methods are used the characteristics of the color are affected by the type of equipment, the method used to calculate the colorimetric characteristics, the conditions of the determination, etc.     

激光彩色墨粉制备方法研究进展

随着对打印品质要求的提高,高质量彩色墨粉的市场需求量越来越大。本文综述了目前激光彩色墨粉的各种制备方法及其优缺点,介绍了聚合法中的乳液聚合和悬浮聚合制备彩色墨粉的方法及研究进展,重点阐述了悬浮聚合法制备墨粉的生产工艺方法及进展,最后对未来墨粉生产工艺及方法进行了展望。作者认为乳液聚合型彩色墨粉具有高分辨率、高色彩饱和度和适宜的固结性能,它将会取代悬浮聚合型彩色墨粉,成为未来墨粉市场的发展趋势。     

Statistical methods for analyzing color difference distributions

Multivalued measurands, such as spectral reflectance and tristimulus values, are usually analyzed by reducing the data to a single‐valued parameter, such as color difference. The variations in sets of color differences are nonnormal distributed. This article compares five statistical methods to determine the 95% tolerance limit on nine data sets of color differences. Published 2010 Wiley Periodicals, Inc. Col Res Appl, 36, 160–168, 2011;     

Centroids of color categories compared by two methods

A 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 the L,j,g coordinate 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 colors.     

色素炭黑表面氧化改性的方法

介绍了色素炭黑表面氧化改性的方法：液相氧化法、气相氧化法、催化氧化和等离子体氧化法,并提出了具有工业应用前景的气相氧化法工艺开发方向。