Additive Primaries: Red, green, and blue. All three colors added together at 100% intensity give you white. Adding cyan, magenta, and yellow at 100% intensity gives you black.
Adobe Color Engine (ACE): - ACE is the color management module (CMM) that was developed by Adobe. The color engine is used to convert image colors from one color space to another (RGB to Lab, for example).
CIE: International Commission on Illumination, the main international organization concerned with color measurement.
CIELAB: Sometimes shortened to "Lab Color". A color space definition in which the values "L", "a", and "b" are plotted to create a three dimensional system representing the color spectrum. "L" represents Lightness; "a" represents the Redness/Greenness axis; and "b" represents the Yellowness/blueness axis. In theory Lab Colors can display all visible colors in the spectrum.
CIE XYZ: The first of a series of mathematical models produced by the CIE (1931) that describe color in terms of synthetic primaries based on human perception.
CMM: (Color Management Module) - The color engine used to drive the color management system (CMS).
Color Separation: The conversion of the green, red, and blue information in an image into cyan, magenta, yellow, and black channels that are used to make plates for four-color press printing.
Color Space: A three dimensional representation of the colors that can be seen or generated using a specific color model (RGB, Lab).
Color Temperature: A measurement of the color of light radiated by an object while it is being heated, measured in degrees Kelvin. Low Kelvin temperatures around 2400K produce red light; high temperature around 9000K are blue. A neutral gray is 6504K.
ColorSync: The color management system for Apple computers. On Windows systems it is ICM.
Colorimeter: An optical measuring instrument that responds to color in a manner similar to the human eye by filtering reflected light into red, blue, and green.
Contrast: The level of variation between light and dark areas in an image.
Cyan: One of the process ink colors for printing. Pure cyan absorbs all red light and reflects all blue and green light.
Device Dependent: Describes the color space thast can only be defined by the color capabilities of a specific device. For example, a monitor has specific capabilities and limitations producing colors. This color space is defined as a device dependent RGB color space.
Device Independent: Describes a color space that includes all possible colors of the spectrum. Lab and XYZ color spaces are device independent.
Device Profiles: Numerical data that characterizes a device's color rendering and reproduction capabilities. Monitor profiles, scanner profiles, and printer profiles are used in a color managed system such as Windows ICM or Apple's ColorSync. Profiles are created by calibration (monitors) and measurement (printers).
Gamut: The range of different colors that can be interpreted by a color model or generated by a specific device.
ICC: (International Color Consortium) - A group of hardware and software vendors dedicated to developing cross-platform standards color communication and consistency.
ICC Profile: A standard format developed by the ICC for a data file that describes the color behavior of an input, display, or output device, or a color model, by referencing it to a device-independent color model such as Lab Color or XYZ Color.
IT8: Series of test targets used to characterize the color information of different devices (scanners, printers).
JPEG: (Joint Photographic Expert Group) - An image compression/decompression standard that divides the image area into cells in order to condense information based on content analysis.
Kelvin: Unit of measurement for color temperature.
Lab Color: A color space used to describe CIE-based color coordinates in a three dimensional model. L=luminance; a+b=two color components.
LUT: (Look Up Table) - A method of converting from one color space into another color space.
Magenta: One of the process ink colors for printing. Pure magenta absorbs all green light and reflects all red and blue light.
Metamerism: A phenomenon where two colors appear to match under one light source but appear not to match when displayed under a different light source.
Out-of-Gamut Colors: Non-reproductible colors, that is, the colors that fall outside the color gamut of printable colors.
Perceptual Rendering: One of the four ICC rendering intents used for handling out-of-gamut colors in a color management system. Perceptual intent compresses all colors in the image but preserves the relationship between all colors.
Pixel: A tiny picture element that contains red, green, and blue information for color rendering on a monitor or a scanner. Monitor resolution is described in terms of pixels per inch (ppi), while the equivalent for print resolution is dots per inch (dpi).
Primary Colors: Red, green, and blue. Same as additive primaries.
Process Printing: Output based from a printing press that uses four colors (cyan, magenta, yellow, and black) to create the illusion of continuous tone images.
Rendering Intent: A method of handling out-of-gamut colors when maching one color space to another. Perceptual and Relative Colorimetric are the most commonly used intents.
RGB: The additive colors, red, green, and blue.
Saturation Rendering: One of the four ICC rendering intents used for handling out-of-gamut colors in a color management system. Saturation intent sacrifices color accuracy in favor of color saturation. Good for producing vivid colorful images.
Spectrophotometer: An instrument that measures color values reflected or transmitted through an object. Commonly used to create quality printer profiles.
Subtractive Primaries: Cyan, magenta, and yellow.
TIFF: (Tagged Image File Format) - A file format developed by Aldus Corp. for exchanging bitmapped images between applications. TIFF or TIF is the most commonly used file format for digital photographs.
Yellow: One of the process ink colors for printing. Pure yellow absorbs all blue light and reflects all red and green light.
White Point: The color usually described in degrees Kelvin and the luminance of the brightest white a given device can reproduce.
