RGB color model

The RGB color model is an additive color model in which red and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red and blue; the main purpose of the RGB color model is for the sensing and display of images in electronic systems, such as televisions and computers, though it has been used in conventional photography. Before the electronic age, the RGB color model had a solid theory behind it, based in human perception of colors. RGB is a device-dependent color model: different devices detect or reproduce a given RGB value differently, since the color elements and their response to the individual R, G, B levels vary from manufacturer to manufacturer, or in the same device over time, thus an RGB value does not define the same color across devices without some kind of color management. Typical RGB input devices are color TV and video cameras, image scanners, digital cameras. Typical RGB output devices are TV sets of various technologies and mobile phone displays, video projectors, multicolor LED displays and large screens such as Jumbotron.

Color printers, on the other hand subtractive color devices. This article discusses concepts common to all the different color spaces that use the RGB color model, which are used in one implementation or another in color image-producing technology. To form a color with RGB, three light beams must be superimposed; each of the three beams is called a component of that color, each of them can have an arbitrary intensity, from off to on, in the mixture. The RGB color model is additive in the sense that the three light beams are added together, their light spectra add, wavelength for wavelength, to make the final color's spectrum; this is opposite to the subtractive color model the CMY color model, that applies to paints, inks and other substances whose color depends on reflecting the light under which we see them. Because of properties, these three colors create white, this is in stark contrast to physical colors, such as dyes which create black when mixed. Zero intensity for each component gives the darkest color, full intensity of each gives a white.

When the intensities for all the components are the same, the result is a shade of gray, darker or lighter depending on the intensity. When the intensities are different, the result is a colorized hue, more or less saturated depending on the difference of the strongest and weakest of the intensities of the primary colors employed; when one of the components has the strongest intensity, the color is a hue near this primary color, when two components have the same strongest intensity the color is a hue of a secondary color. A secondary color is formed by the sum of two primary colors of equal intensity: cyan is green+blue, magenta is blue+red, yellow is red+green; every secondary color is the complement of one primary color. The RGB color model itself does not define what is meant by red and blue colorimetrically, so the results of mixing them are not specified as absolute, but relative to the primary colors; when the exact chromaticities of the red and blue primaries are defined, the color model becomes an absolute color space, such as sRGB or Adobe RGB.

The choice of primary colors is related to the physiology of the human eye. The normal three kinds of light-sensitive photoreceptor cells in the human eye respond most to yellow and violet light; the difference in the signals received from the three kinds allows the brain to differentiate a wide gamut of different colors, while being most sensitive to yellowish-green light and to differences between hues in the green-to-orange region. As an example, suppose that light in the orange range of wavelengths enters the eye and strikes the retina. Light of these wavelengths would activate both the medium and long wavelength cones of the retina, but not equally—the long-wavelength cells will respond more; the difference in the response can be detected by the brain, this difference is the basis of our perception of orange. Thus, the orange appearance of an object results from light from the object entering our eye and stimulating the different cones but to different degrees. Use of the three primary colors is not sufficient to reproduce all colors.

The RGB color model is based on the Young–Helmholtz theory of trichromatic color vision, developed by Thomas Young and Hermann von Helmholtz in the early to mid-ninetee


Work-to-rule is a job action in which employees do no more than the minimum required by the rules of their contract, follow all safety or other regulations, which may cause a slowdown or decrease in productivity, as they are no longer working during breaks or during unpaid extended hours and weekends. Such an action is considered less disruptive than a strike or lockout, obeying the rules is less susceptible to disciplinary action. Notable examples have included nurses refusing to answer telephones, teachers refusing to work for free at night and during weekends and holidays, police officers refusing to issue citations. Refusal to work overtime, travel on duty, or sign up to other tasks requiring employee assent are other manifestations of using work-to-rule as industrial action. Sir John Donaldson described it as a decision to "ive the rules a meaning which no reasonable man could give them and work to that."Sometimes the term "rule-book slowdown" is used in a different sense than "work-to-rule": the former involves applying to-the-letter rules that are set aside or interpreted less to increase efficiency.

Work-to-rules can be misconstrued as malicious when it is only a removal of good-will, such as employees insisting on taking all entitled breaks, or refusing a request to work unpaid overtime. Sometimes work-to-rule can be considered by employers as malicious compliance as they pursue legal action against workers. While not enforceable under minimum statutory law, employers may enforce customized employment contract terms that the employee agreed to: Overtime is waived in part, in whole, or converted to time-in-lieu Breaks are set by management Job description includes "ad-hoc task" or "as assigned" Termination for any reasonThey may take standard forms of action where custom terms were not negotiated during the offer: Warning and noting employee file for professional misconduct or insubordination Reassigning employee to insignificant, routine, or mundane tasks Malicious compliance "Work-to-rule: a guide". 11 November 2006. Retrieved 12 January 2019

Parco naturale regionale delle Alpi Liguri

The Alpi Liguri Natural Regional Park is a natural park in Province of Imperia. It was established in 2007 by the legge regionale nr.34 of 15/11/2007. Situated in the inland of Ventimiglia and Sanremo area, the regional park protects some of the most beautiful and important areas of the Ligurian Alps; the protected territory, over 60 square kilometres, includes four separate areas, each with its particular features: Zona di Pian Cavallo: located in the North of the park along the border with Piemonte, it includes the Bosco delleNavette and some natural caves. Dorsale Monte del Monte Saccarello - Monte Frontè - Monte Monega: is the highest part of the park with wide grazing areas. Comprensorio del Monte Gerbonte - M. Toraggio/Pietravecchia: the area hosts the 600 ha Foresta Demaniale of Gerbonte and, on the mountains of the French-Italian border, a wide variety of microclimates. Foresta Demaniale di Testa d'Alpe: is the southernmost part of the park, just some 15 km from the Ligurian Sea; some territories connecting these areas are under a lesser form of environmental protection named paesaggio protetto.

The natural park is shared among seven different municipalities: Cosio di Arroscia, Montegrosso Pian Latte, Rezzo, Rocchetta Nervina, Triora. Most of the protected area is covered by sedimentary rock mountains, with the predominant type of bedrock represented by flysch. Mountains and valleys of the park, due to their proximity to the sea, are home to a wide wildlife variety. Rare mammals in the park include stoats, mountain hares, European pine martens and European snow voles, as well as wolves and wildcats. Among birds can be noticed the presence of the black woodpecker and Eurasian eagle-owl, the biggest European bird of prey. In the woods neststhe black grouse, the eagle, although close to the limit of its geographic range, lives on the park's cliffs; the caves located in the park host a good variety of bats. A wide range of footpaths is available within the park, crossed from south-west to east by the Alta Via dei Monti Liguri, a long-distance trail from Ventimiglia to Bolano. Pages by the Park Authority on Official site