|
Color Reproduction
Color reproduction is an aspect of color science concerned with producing light spectra that evoke a desired color, either through additive (light emitting) or subtractive (surface color) models. It converts physical correlates of color perception ( CIE 1931 XYZ color space tristimulus values and related quantities) into light spectra that can be experienced by observers. In this way, it is the opposite of colorimetry. It is concerned with the faithful reproduction of a color in one medium, with a color in another, so it is a central concept in color management and relies heavily on color calibration. For example, food packaging must be able to faithfully reproduce the colors of the foods therein in order to appeal to a customer. This involves proper color calibration of at least four devices: * Lighting, which must have a high color rendering index and not give a color cast to the object. * Camera, which measures the reflected spectrum of the object and converts to a trichromati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Process Control Patch
A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management *Business process, activities that produce a specific service or product for customers *Business process modeling, activity of representing processes of an enterprise in order to deliver improvements *Manufacturing process management, a collection of technologies and methods used to define how products are to be manufactured. *Process architecture, structural design of processes, applies to fields such as computers, business processes, logistics, project management *Process costing, a cost allocation procedure of managerial accounting * Process management, ensemble of activities of planning and monitoring the performance of a business process or manufacturing processes *Process management (project management), a systematic series of activities directed towards causing an end result in engineeri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Science
Color science is the scientific study of color including lighting and optics; measurement of light and color; the physiology, psychophysics, and modeling of color vision; and color reproduction. History Organizations * International Commission on Illumination (CIE) * Illuminating Engineering Society (IES) * Inter-Society Color Council (ISCC) * Society for Imaging Science and Technology (IS&T) * International Colour Association (AIC) * Optica, formerly the Optical Society of America (OSA) * The Colour Group * Society of Dyers and Colourists (SDC) * American Association of Textile Chemists and Colorists (AATCC) * Association for Research in Vision and Ophthalmology (ARVO) * ACM SIGGRAPH * Vision Sciences Society (VSS) * Council for Optical Radiation Measurements (CORM) Journals The preeminent scholarly journal publishing research papers in color science is '' Color Research and Application'', started in 1975 by founding editor-in-chief Fred Billmeyer, along with Gunte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a color space, colors can be identified numerically by their coordinates. Because perception of color stems from the varying spectral sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully explain the psychophysical perception of color appearance. Color science includes the perception of color by the eye and brain, the origin of color in materials, color theory in art, and the physics of electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Additive Color
Additive color or additive mixing is a property of a color model that predicts the appearance of colors made by coincident component lights, i.e. the perceived color can be predicted by summing the numeric representations of the component colors. Modern formulations of Grassmann's laws describe the additivity in the color perception of light mixtures in terms of algebraic equations. Additive color predicts perception and not any sort of change in the photons of light themselves. These predictions are only applicable in the limited scope of color matching experiments where viewers match small patches of uniform color isolated against a grey or black background. Additive color models are applied in the design and testing of electronic displays that are used to render realistic images containing diverse sets of color using phosphors that emit light of a limited set of primary colors. Examination with a sufficiently powerful magnifying lens will reveal that each pixel in CRT, L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtractive Color
Subtractive color or subtractive color mixing predicts the spectral power distribution of light after it passes through successive layers of partially absorbing media. This idealized model is the essential principle of how dyes and inks are used in color printing and photography where the perception of color is elicited after white light passes through microscopic "stacks" of partially absorbing media allowing some wavelengths of light to reach the eye and not others. Process The subtractive color mixing model predicts the resultant spectral power distribution of light filtered through overlaid partially absorbing materials on a reflecting or transparent surface. Each layer partially absorbs some wavelengths of light from the illumination spectrum while letting others pass through, resulting in a colored appearance. The resultant spectral power distribution is predicted by sequentially taking the product of the spectral power distributions of the incoming light and transmissiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CIE 1931 Color Space
The CIE 1931 color spaces are the first defined quantitative links between distributions of wavelengths in the electromagnetic visible spectrum, and physiologically perceived colors in human color vision. The mathematical relationships that define these color spaces are essential tools for color management, important when dealing with color inks, illuminated displays, and recording devices such as digital cameras. The system was designed in 1931 by the ''"Commission Internationale de l'éclairage"'', known in English as the International Commission on Illumination. The CIE 1931 RGB color space and CIE 1931 XYZ color space were created by the International Commission on Illumination (CIE) in 1931. They resulted from a series of experiments done in the late 1920s by William David Wright using ten observers and John Guild using seven observers. The experimental results were combined into the specification of the CIE RGB color space, from which the CIE XYZ color space was derived. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorimetry
Colorimetry is "the science and technology used to quantify and describe physically the human color perception". It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color perception, most often the CIE 1931 XYZ color space tristimulus values and related quantities. History The Duboscq colorimeter was invented by Jules Duboscq in 1870. Instruments Colorimetric equipment is similar to that used in spectrophotometry. Some related equipment is also mentioned for completeness. * A tristimulus colorimeter measures the tristimulus values of a color. * A spectroradiometer measures the absolute spectral radiance (intensity) or irradiance of a light source. * A spectrophotometer measures the spectral reflectance, transmittance, or relative irradiance of a color sample. * A ''spectrocolorimeter'' is a spectrophotometer that can ''calculate'' tristimulus values. * A densitometer measures the degree of light ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Management
In digital imaging systems, color management (or colour management) is the controlled conversion between the color representations of various devices, such as image scanners, digital cameras, monitors, TV screens, film printers, computer printers, offset presses, and corresponding media. The primary goal of color management is to obtain a good match across color devices; for example, the colors of one frame of a video should appear the same on a computer LCD monitor, on a plasma TV screen, and as a printed poster. Color management helps to achieve the same appearance on all of these devices, provided the devices are capable of delivering the needed color intensities. With photography, it is often critical that prints or online galleries appear how they were intended. Color management cannot guarantee identical color reproduction, as this is rarely possible, but it can at least give more control over any changes which may occur. Parts of this technology are implemented in the ope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Calibration
The aim of color calibration is to measure and/or adjust the color response of a device (input or output) to a known state. In International Color Consortium (ICC) terms, this is the basis for an additional color characterization of the device and later profiling. In non-ICC workflows, calibration refers sometimes to establishing a known relationship to a standard color space in one go. The device that is to be calibrated is sometimes known as a ''calibration source''; the color space that serves as a standard is sometimes known as a ''calibration target''. Color calibration is a requirement for all devices taking an active part of a color-managed workflow, and is used by many industries, such as television production, gaming, photography, engineering, chemistry, medicine and more. Information flow and output distortion Input data can come from device sources like digital cameras, image scanners or any other measuring devices. Those inputs can be either monochrome (in which c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Rendering Index
A color rendering index (CRI) is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with a natural or standard light source. Light sources with a high CRI are desirable in color-critical applications such as Neonatal nursing, neonatal care and Conservation and restoration of cultural property, art restoration. It is defined by the International Commission on Illumination (CIE) as follows: Color rendering: Effect of an Light#Light sources, illuminant on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference or standard illuminant. The CRI of a light source does not indicate the apparent color of the light source; that information is given by the Color temperature, correlated color temperature (CCT). The CRI is determined by the light source's spectrum. An incandescent lamp has a continuous spectrum, a fluorescent lamp has a discrete Emission sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Cast
A colour cast is a tint of a particular colour, usually unwanted, that evenly affects a photographic image in whole or in part. Certain types of light can cause film and digital cameras to render a colour cast. Illuminating a subject with light sources of different colour temperatures will usually cause colour cast problems in the shadows. The human eye generally does not notice the unnatural colour, because our eyes and brains adjust and compensate for different types of light in ways that cameras cannot. In film, colour casts can also be caused by problems in photo development. Improper timing or imbalanced chemical mixtures can cause unwanted casts. Colour casts can also occur in old photographs due to fading of dyes, particularly under the action of ultraviolet light. These may be correctable on a scanned version of the photograph with image editing techniques. Solutions Most digital cameras try to automatically detect and compensate colour cast and usually have a selec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Vision
Color vision, a feature of visual perception, is an ability to perceive differences between light composed of different wavelengths (i.e., different spectral power distributions) independently of light intensity. Color perception is a part of the larger visual system and is mediated by a complex process between neurons that begins with differential stimulation of different types of photoreceptors by light entering the eye. Those photoreceptors then emit outputs that are propagated through many layers of neurons and then ultimately to the brain. Color vision is found in many animals and is mediated by similar underlying mechanisms with common types of biological molecules and a complex history of evolution in different animal taxa. In primates, color vision may have evolved under selective pressure for a variety of visual tasks including the foraging for nutritious young leaves, ripe fruit, and flowers, as well as detecting predator camouflage and emotional states in other pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
