1,898 research outputs found

    Status of CIE Color Appearance Models

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    In meetings just prior to the 1997 AIC Congress in Kyoto, CIE TC1-37, chaired by M. Fairchild, established the CIE 1997 Interim Colour Appearance Model (Simple Version), known as CIECAM97s. CIECAM97s was formally published in 1998 in CIE publication 131. CIE TC1-37 was dissolved shortly after publication of CIECAM97s at which time, a reportership, R1-24 held by M. Fairchild, was established to monitor ongoing developments in color appearance modeling and notify CIE Division 1 if it became necessary to form a new TC to consider revision or replacement of CIECAM97s. In the four years between AIC Congresses, there has been much activity, both by individual researchers and within the CIE, aimed at furthering our understanding of color appearance models and deriving improved models for consideration. The aim of this paper is to summarize these activities, report on the current status of CIE efforts on color appearance models, and suggest what the future might hold for CIE color appearance models

    Spectral Adaptation: A Reason to Use the Wavenumber Scale

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    Chromatic adaptation refers to the ability of the human visual system to adjust to the color of the illumination, or other prevailing stimuli, such that perceived object colors vary far less with changes in illumination than would be expected from simple radiometry or colorimetry. Models of chromatic adaptation are generally formulated as extensions of the von Kries hypothesis of some sort of independent gain control mechanisms operating on the three types of cone signals. This paper introduces a new way to model the phenomenon with no requirement for the first stage chromatic processing. This model is referred to as a spectral adaptation model since it acts upon spectra rather than chromatic signals such as tristimulus values. The spectral adaptation model was compared with other models of adaptation both computationally and through limited psychophysical data. It is shown to have reasonable, and flexible, performance and could be of practical value in applications such as spectral image reproduction. A limiting case of the spectral model, a model of perfect color constancy, is also described and compared with traditional chromatic adaptation models

    The Geographic and Social Mobility of Slaves: The Rise of Shajar al’Durr, A Slave-Concubine in Thirteenth-Century Egypt

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    Large numbers of outsiders were integrated into premodern Islamic society through the institution of slavery. Many were boys of non-Muslim parents drafted into the army, and some rose to become powerful political figures; in Egypt, after the death of Ayyubid sultan al-Salih (r. 1240–49), they formed a dynasty known as the Mamluks. For slave concubines, the route to power was different: Shajar al-Durr, the concubine of al-Salih, gained enormous status when she gave birth to his son and later governed as regent in her son’s name, converting to Islam after her husband’s death and then reigning as sultan in her own right. She emerges as a figure both unique and typical of the pathways to assimilation and mobility

    A Color Scientist Looks at Video

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    This paper represents a critical review of some of the color processing in the consumer TV processing chain. As such, a default processing chain is assumed as a starting point. The flow of color image information through this chain is described and critiqued. That is followed by development and description of some “clean slate” theoretical approaches to video processing with color accuracy and quality as the highest priority. These two approaches are compared and contrasted to provide some practical insight into how color science could be used in a practical sense to improve consumer video processing. Additionally, some examples how color and image appearance models might be used in the development of consumer video systems are described

    First Steps Toward Change in Teacher Preparation for Elementary Science

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    Unless introductory undergraduate science classes for prospective elementary teachers actively incorporate the philosophy of inquiry-based learning called for in K-l2 science education refom little will change in elementary science education. Thus, at James Madison University, we have developed a new integrated science core curriculum called Understanding our World [1]. This course sequence was not only designed to fulïŹll general education science requirements. but also to focus on content areas our students will need to know as teachers. The objectives of these courses are based on the National Science Education Standards and Virginia’s Science Standards of Learning, including earth and space science, chemistry, physics, life sciences, and environmental science [2,3]. As an integrated package, this course sequence addresses basic science content, calculation skills, the philosophy and history of science, the process of how science is done, the role of science in society, and applications of computers and technology in science. Keeping in mind that students tend to teach in the same way they were taught, Understanding our World core classes embrace the concepts associated with reform in elementary math and science

    Knowledge of and attitudes to sports drinks of adolescents living in South Wales, UK

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    Background: The UK sports drinks market has a turnover in excess of £200M. Adolescents consume 15.6% of total energy as free sugars, much higher than the recommended 5%. Sugar sweetened beverages, including sports drinks, account for 30% of total free sugar intake for those aged 11-18 years. Objective: To investigate children’s knowledge and attitudes surrounding sports drinks. Method: 183 self-complete questionnaires were distributed to four schools in South Wales. Children aged 12 - 14 were recruited to take part. Questions focussed on knowledge of who sports drinks are aimed at; the role of sports drinks in physical activity and the possible detrimental effects to oral health. Recognition of brand logo and sports ambassadors and the relationship of knowledge to respondent’s consumption of sports drinks were assessed. Results: There was an 87% (160) response rate. 89.4% (143) claimed to drink sports drinks. 45.9% thought that sports drinks were aimed at everyone; approximately a third (50) viewed teenagers as the target group. Over 2/3rds recognised the brand logos, yet less than a 1/3rd could identify brand ambassadors. About half were aware that dental erosion may result from consumption and approximately 2/3rds knew that they were linked to dental caries and energy provision. Despite this the majority claimed to drink them. As previously reported most of those drinking sports drinks did so because of the taste. Conclusion: Whilst most of the respondents had some understanding of the detrimental effects on health the majority of them were drinking them regularly despite this knowledge. Work is therefore needed at a macro level, with soft drink manufacturers, to consider marketing and reformulation of products for adolescent consumers who appear to enjoy them

    Observer metamerism: Why do [mis]matches of neutral appear pinkish or greenish?

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    White lighting and neutral-appearing objects are essential in numerous color applications. In particular, setting or tuning a reference white point is a key procedure in both camera and display applications. Various studies on observer metamerism pointed out that noticeable color disagreements between observers mainly appear in neutral colors. Thus, it is vital to understand how observer metamers of white (or neutral) appear in different colors by different observers. Most observers who participated in a visual demonstration reported that white observer metamers appear pinkish or greenish but rarely yellowish or bluish. In this paper, this intriguing question, “Why observer metamers of white are usually pinkish or greenish?,” is addressed based on simulations. Besides, it is also analyzed that which physiological factors play an essential role in this phenomenon and why it is less likely for humans to perceive yellowish or bluish observer metamers of white
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