Color is everywhere in daily life. It makes the world vibrant and exciting. However, we frequently make difficult color decisions and struggle to describe them precisely. Color on its own spans physics, chemistry, computing, psychology, and perception, and contributes fundamentally to art, design, and media.With this in mind, the primary goal of this publication was to provide a comprehensive and multidisciplinary reference to the main fields in which color is relevant. It can be used to promote the fields of color science and technology, to cover a wide range of disciplines, to provide good introductory material for beginners, and to attract a new generation of color researchers and engineers. I am very proud to say we have successfully achieved this goal.
Readers will be able to survey information on color related subjects from many different aspects and influence the way people work with color. It has been a great honor and pleasure to coordinate this ambitious project. As an educator in the field of color technology, I have been fortunate to lead the project that includes 14 sections divided into 254 chapters. In total, 153 experts were invited to contribute to the work. This is the first reference work to refer to color from the different points of view of color vision, color appearance, optical phenomena, colorants, metrology, color spaces, and many other color related topics. It also includes domain specific entries such as color and visualization, color in graphics, image processing, and color management.
Readers can access each topic as a printed reference and also as part of Springer online reference material. In addition, each author will continue to update their material for years to come. Although a substantial amount of work has been accomplished, it is planned to extend the encyclopaedia to include new content as it becomes relevant and available.
I would like to thank all the contributors, including the section leaders, who each assembled a strong group of authors in their specific expert areas, and all the authors who prepared high quality input in a timely manner. I would like to particularly thank Prof. van Bommout who almost single handedly delivered the section on lighting technology based on his vast knowledge of the subject. I would also like to thank the late Prof. Janos Schanda for leading the section on CIE standards. It is with sadness that we learnt he had passed away during a busy period of preparation: he will be greatly missed by all color people.
About the Editor
Over the past 30 years, Ming Ronnier Luo has been involved in the field of color science and color technology. His major contributions to color science include advances in color difference evaluation, color appearance modeling, color emotion and harmony understanding and prediction, and lighting quality measurement. His mission has always been one of international dissemination of color expertise. He has created color and appearance postgraduate departments at universities in China, Taiwan, and UK, and currently he is a Global Expertise Professor at Zhejiang University (China), the Professor of Color and Imaging Science at the University of Leeds (UK), and a Chair Professor at the National Taiwan University of Science and Technology (R.O.C.). He and his colleagues have copublished over 500 refereed journal and conference papers. He has successfully supervised 45 PhD students and has taught color science courses to over 500 master students. These are now spread across all continents in academic institutions and industry. He has been heavily involved with the International Commission on Illumination (CIE), the world authority for the standardization and specification of color and lighting, presently holding the post of Vice President Publishing (2015–2019). He served the Director of CIE Division One on Vision and Color (2007–2015), and a chair or an active member of various technical and standardization committees. He was also Chairman of the Color Measurement Committee of the Society of Dyers and Colorists (1997–2002).
Ronnier has always worked closely with industry and strongly believes in the transfer of technology. Many of his new technologies have become successful industrial products, collaborating with international companies covering the surface color, imaging, and illumination and supply chain industries.
In recognition of his contributions to color science and technology, he has gained a number of awards. These include the Dyers’ Company Silver Medal (1986–1987), The Bartleson Research Award (1994), and the Davis Medal of the Royal Photographic Society (2003). He was awarded the title of Fellow of the Society of Dyers and Colorists in 2000, their Centenary Medal in 2004, and their Gold Medal in 2009. He became a Fellow of the Society of Image Science and Technology (2002) and the Dyers’ Company Research Medallist in (2006).
Adaptation is a response modification of the visual system to light stimulation. The human visual system (HVS) changes its sensitivity as a function of the evolution over time of the observed scene and therefore has an evolution over time itself. Once the observed scene has stopped changing, the adaptation process continues until it becomes complete and then stops. The notation “adaptation” is used both for the process of adjustment as well as for the end state of complete adaptation. CIE ILV defines: State of Adaptation State of the visual system after an adaptation process has been completed.
NOTE The terms light adaptation and dark adaptation are also used, the former when the luminances of the stimuli are of at least 10 cd/m2 and the latter when the luminances are of less than some hundredths of a cd/m2.
The HVS, after being adapted to a bright light, may need a time in the order of more than one half hour to become completely dark adapted, while, after being adapted to darkness, it may need only a few minutes to become completely daylight adapted. These two processes are not symmetrical and are considered separately. Dark adaptation is at the basis of the duplicity theory that states that two transduction mechanisms exist, which are related to two different kinds of photosensitive cells: the rods and the cones. In each retina, there are approximately between 75 and 150 million rods and six to seven million cone cells . The rods are extremely sensitive to light; they contain rhodopsin as the light-absorbing pigment responsible for the transduction and provide achromatic vision. The cones are of three different classes (L cones, Mcones, S cones) containing three different lightabsorbing pigments responsible for the transduction. They are less sensitive than the rods and provide color vision. The distributions of cones and rods on the retina are very different and very nonuniform.