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Implementation of Machine Learning in Color Perception and Psychology: A Review
Published in Rekh Ram Janghel, Rohit Raja, Korhan Cengiz, Hiral Raja, Next Generation Healthcare Systems Using Soft Computing Techniques, 2023
Mitra, Dipannita Basu, Ahona Ghosh
Color perception requires two elements, an illuminant and an observer, to grasp the object's color. Connivance between an illuminant and an observer is required, where the observer is the human encephalon [1]. The encephalon amasses the knowledge from each group of receptors, which gives rise to distinct perceptions of various wavelengths of light. In the human eye, cones and rods are not uniformly dispersed. The various wavelengths of visible light, such as red, are perceptible primarily at around 700 nanometers. The color violet's wavelength is 380 nanometers, which is short and frequent. Various colors invoke the feeling of happiness in the observer [2]. A happy color produces more satisfaction than perceived, an effect known as affective contrast enhancement. When a person views a dull-colored object, the light reflected activates the ocular process in the eye because contrasting illuminants have divergent spectral energy scattering, which is called color constancy—using light as a parameter of high- and low-intensity categorization of various colors carried out using machine learning and computer vision algorithms. Color blindness is a term given to the condition where individuals have trouble discriminating variations of color. It is not the shortcoming of the eye; instead, it is an obstruction of the brain, and the term is ambiguous because a person with color blindness is not blind. The association between color and emotion has possible comparability across cultures based on emotion surveys.
Did the Ancient Greeks perceive the color ‘blue’? An interdisciplinary approach
Published in Mário S. Ming Kong, Maria do Rosário Monteiro, Maria João Pereira Neto, Creating Through Mind and Emotions, 2022
In 1601, Guido Antonio Scarmiglioni proposed the existence of five simple colors, from which all others were obtained. At that time, he could only be considering color-pigment mixtures: However, in 1855, Maxwell showed that just three types of light were needed to create almost any color: red-orange, blue-violet, and green: in mixing light rays of different wavelengths, color is synthesized through the addition of several components, which together stimulate the retina to create a particular color sensation in an additive mixture. Colors that are obtained from mixtures between primaries are called secondary colors. Mixtures of color light are additive and differ from mixtures of color pigments, which are subtractive. Newton systematized the spectrum by separating the brightest or “simple” colors from the “composite” or intermediate colors: there are seven simple or primary colors when effectively the spectrum is a continuous gradation of colors that mix. The naming of colors in this continuum can be done according to a variety of chromatic principles.
An Introduction To Light
Published in Craig DiLouie, Lighting Redesign for Existing Buildings, 2020
Color temperature describes the “whiteness,” “bluishness”, etc. of a light source—its warmth or coolness. However, it does not define how natural the color of objects will appear when lighted by the source. Two light sources can have the same color temperature, but render colors differently. The color rendering index (CRI), a rating scale with a maximum of 100, offers a metric to address this. For most common color temperatures, CRI uses a blackbody radiator as the reference for color rendering (assumed 100 CRI). Daylight has a CRI of 100, with incandescents coming in a close second. Incandescent lamps, however, are not a perfect light source for color rendering (they are weak in blue), so the CRI system has its drawbacks. It is, however, the only internationally agreed upon system for expressing a lamp’s color rendering ability. It should only be used as an indicator of relative, not absolute, color rendering ability.
A common type of commercially available LED light source allows for colour discrimination performance at a level comparable to halogen lighting
Published in Ergonomics, 2019
Sara Königs, Susanne Mayr, Axel Buchner
Light sources based on light emitting diodes (LEDs) have become superior to other conventional light sources such as incandescent, halogen, or fluorescent lamps in terms of lifetime and efficiency (Chang et al. 2012). The efficiency of a light source is characterised by its luminous efficacy which is defined as the ratio of the luminous flux to the electrical power consumption (Boyce 2014), measured in lumens per watt (lm/W). Apart from luminous efficacy and lifetime, LED-based light sources differ from other conventional light sources in their spectral power distribution. The spectral power distribution reflects the intensity of emitted radiation at each wavelength (Houser et al. 2016). Radiation in the wavelength range from 380 to 780 nm (the visible spectrum) leads to a response of the human visual system (Boyce 2014) and thus triggers the perception of colour; for normal observers short wavelengths appear as blue light, medium wavelengths as green light, and long wavelengths as red light (Houser et al. 2016).
Dye adsorption and intensity in bobbin crusade in dyeing mixed acrylic and cotton yarn
Published in The Journal of The Textile Institute, 2021
Catia Rosana Lange de Aguiar, Antonio Augusto Ulson de Souza, Selene Maria Arruda Guelli Ulson de Souza
Color is a word that describes an uneven distribution of radiant energy, visible by the eyes, from a light source reflecting from objects. Chemically, it is the result of a reaction that occurs with some molecules, affording groups which when electronically excited emit characteristic radiation (Farkas, 2001). To assess color intensity, the yarn samples were measured on an X-Rite brand color spectrophotometer. The color intensity was determined by the spectral reflectance curve, which represents the identity of a color. In this study, the color intensity in percentage was measured in CMC language (Color Measurement Committee).
Lighting Effects on Older Adults’ Visual and Nonvisual Performance: A Systematic Review
Published in Journal of Housing For the Elderly, 2019
Xiaojie Lu, Nam-Kyu Park, Sherry Ahrentzen
The study by Figueiro and colleagues (2008b) examined effects of a 24-hour lighting scheme on older adults’ sleep quality. This study selected four bedrooms in a long-term care facility. Before installation, all the lamps were incandescent. Newly installed lamps set the living room with illuminance level ranging from 200 to 475 lux at cornea and with cooler color temperature (6500 K) during daytime. Color temperature is the color appearance (warm or cool) of a light source measured in degrees Kelvin (K) (ANSI/IES RP-28–16, 2016). The newly added lighting system with timers turned on lights approximately from 6:45 to 18:00, and then turned off lights at 18:00 (only low-illuminance-level incandescent lamps allowed). This purpose of the lighting system is to give cooler color temperature and higher illuminance level during daytime and warmer color temperature and lower illuminance level at night. In the study, 10 female participants were recruited. However, only four completed the study, with age ranging from 80 to 98 years. The Pittsburg Sleep Quality Index (PSQI) questionnaire evaluated older adults’ sleep quality subjectively, and actigraphs measured rest/activity rhythms objectively. Dependent variables, subjective and objective sleep quality, were collected twice: once before the installation of a new light system and once after installation. The t-test results showed (a) no statistically significant difference between the PSQI before and after the lighting intervention; (b) although sleep efficiency did not reach statistical significance, descriptive statistics showed sleep efficiency increased after the lighting intervention. Given the very small sample size of four individuals, caution needs to be given to the results. Nonetheless, the study does lend support to researchers and designers exploring and further validating new lighting systems for sleep quality.