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Back to Issue 431
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Color Research and Application
In This Issue, February 2008
Ralph A. Stanziola, who served as Color Research and Application’s Special Editor for Industrial Applications for ten years, died. We begin this issue by paying tribute to him. I am not alone in saying I looked up to Ralph as a mentor and colleague, and I shall miss him greatly.
Moving on to our articles, Rolf Kuehni leads off with the first article in a series on “Forgotten pioneers of color order.” The pioneer highlighted in this article, Gaspard Grégoire, who lived from 1751 to 1846, developed a color order system using hue, chroma, and lightness.
In our next article Farnaz Agahian and Seyed Hossein Amirshahi introduce a new
approach to color matching based on principal component analysis. Traditional
algorithms match spectral values or colorimetric values. This new method matches “the
most variation” of a given spectrum by equalizing the first three coordinates
of the principal components. It is described in “A New Matching
Strategy: Trial the Principal Component Coordinates.” Using this approach, the formulation results
in a lower degree of metamerism directly.
Our next three articles are on perception
and color appearance. First Yoshinobu Nayatani and Hideaki Sakai discuss the “Relationship
between Zero-Grayness Luminance and Perceived Brightness of Spectrum Colors.” In
the 1960s Ralph Evans wrote two articles on the chromatic strength of colors
and proposed the concept of grayness of light, which is described in his book
Introduction to Color. In their article, Drs. Nayatani and Sakai not only examine
the relationship between zero-grayness and perceived brightness, as the title
suggests, but also point out some important contradictions that require further
research.
Next “Using Symmetry to Understand the Attributes of Color,” Louis
Adams discusses the symmetries of the common color attributes of hue, saturation,
chroma, chromaticness, whiteness, and blackness. According to Adams, symmetries
provide a simplified framework for calculating groups of colors that share color
attributes. He then goes on to examine color models including the Hunt Model,
a simple color model, various CIE color spaces, and the IPT space which is part
of iCAM. A general functional form describes symmetries and scaling laws for
many of the color models, and exceptions are discussed in this article.
Thirdly, Gábor Kutas and Peter Bodrogi discuss the “Colour appearance of a large homogenous
visual field.” In this article, they describe an experiment in which large (85º)
colored field are compared to small patches of color (2º and 10º). They go on
to model the effects that they find, and compare their results to those of other
researchers. Adaptation and how it is handled is an important parameter in this
research, especially when some of the stimuli are a significant portion of one’s
visual field.
Our last three articles relate to architecture in one way or another.
From perceived appearance, we move to the application of appearance in color
selection. In “Aesthetic Decision-making” Lucila R. Geymonat de Destefani and
T. W. Allan Whitfield examined the process by which a choice of color is made.
In their study the choice being investigated was selection of color paint for
a room. Although the process in not the same for all people, they found that
it consists of two essential stages. The first stage involves deciding what qualities
are sought. Once this is decided, the second stage of matching color attributes
to that specification is undertaken. This process has much in common with parallels
in the decision research field of naturalistic decision making.
Our next article
described a new approach for taking areal measurement of soiling on historic
walls and buildings. In “Grayscale Calibration of Outdoor Photographic Surveys,” M.
J. Thornbush describes how, using a grayscale as a constant in photographic surveys,
measurements on flat outdoor surfaces to track changes in the lightness and chroma
of buildings were made, thus making it possible to follow the amount of soiling
occurring on the façade. The simple grayscale calibration improves the comparability
of surveys to spectrophotometric measurements.
Our last full-length article
discusses urban color, a “hot” topic in China currently. In 2000, the Beijing
Municipal Peoples Government issued a regulation that in order to create a steady-going,
broad and simple but elegant urban environment, the color of building façades
in Beijing should assume a compound color based on gray. This touched off much
discussion. Thus Aiping Gou and Jiangbo Wang decided to research what has been
done about color in urban planning in Eastern China. They report the results
in “Research on the Location Characters of Urban Color Plan in China.” The authors
conclude among other things that under present Chinese urban plan system, the
urban color plan is the result of the game between urban planners and architects
which come out from the rapid boom of urban construction and economy development.
In a Note in the Communications and Comments section, Ralph Pridmore asks, “Chromatic
induction: opponent color or complementary color process? Mr. Pridmore points
out that currently chromatic induction is considered to be an opponent process,
but 50 years ago it was accepted as a complementary color process. While that
was never disputed, it was apparently overlooked. I encourage readers to take
another look, by reading Pridmore’s note.
Also in our Communications and Comments section the discussion on camera
color gamut continues. Robert W. G. Hunt and Michael R. Pointer suggest “Camera
Colour Analysis Gamut.” “Try Camera Gamut again: Not for size, but for camera+profile
Evaluation.” replies Michael H. Brill, who started this discussion last year
in Issue #3.
Finally in this issue we have two book reviews, a meeting report,
and some news from RIT. Sandra Austin reviews the book, Color Influencing Form
by Roy Osborne. Françoise Viénot tells us about Dictionnaire des termes de la
COULEUR written by our own Associate Editor from France, Robert Sève, Michel
Indergand, and Philippe Lanthony. Slava Jeler and Dunja Legat report on the 7th
International Symposium of Slovenian Colorists Association. The topic Color of
National Symbols, focused on the reproduction of national symbols on different
materials, the definition and quality control of the color. Last Rochester Institute
of Technology invites applicants for its masters and doctoral programs in Color
Science and also for their industrial short-courses in color.
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