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HD Ultra X Service Guide
Centre Internationale d'Eclairage (CIE) is an international organization that establishes methods for
measuring color. These color standards for color-metric measurements are internationally accepted
specifications that define color values mathematically. The first color space model, the CIE xyz, was
developed in 1931. CIE defines color as a combination of three axes: x, y and z. The two color spaces
released in 1978 are CIE Lab and CIE Luv. The goal was to provide an accurate and uniform reference of
visual perception.
CMYK
The subtractive printing colors. Cyan, Magenta, Yellow, Black.
Color Balance
The visual effect of an image when the amount of each color and the overall amount of color are
balanced.
Color bit depth
The simplest pixel has two options: black or white. (A pixel with two choices is known as a 1-bit image, or
two raised to the power of one). Adding more bit information increases the number of color options. The
number of potential color options for a pixel is called color bit depth. For example a 4-bit pixel would have
16 color options, and an 8-bit pixel would have 256 color options, while a 24-bit pixel would have
16,777,216 color options.
Color Cast
An image is said to have a color cast if its colors are not true. A color cast will usually be described by
stating the particular color predominant in the image, e.g., the grass appears to have a red color cast.
Color Correction
To improve the color rendition. Correcting for, and eliminating an unwanted color cast.
Color Management System
Color Management System (CMS) software in-creases the accuracy of color interchange between
scanners, displays and printers based on profiles for each device. The CMS is a layer of software resident
on the computer that negotiates color reproduction between the application and color devices. The CMS
performs the color transformations necessary to exchange accurate color between diverse devices. The
Color manager needs access to characterization data for the device. The format and content of such
device profiles is standardized by the International Color Consortium (ICC.)
Color Separation
Process of separating colors, in an image, into primary color components for printing. Converting an RGB
color image into CMYK color image. Color separation is a technical function during which critical settings
such as GCR, black ink limit and total ink limit are applied to the image.
Color Space
A color space is a particular language used to describe color. Examples of color spaces are: RGB, CMYK,
HSV, CIE LAB.
Contrast
The difference between the lightest and darkest significant areas in a picture. A picture with high contrast
has nearly white areas and nearly black areas with sharp changes in brightness between them. The
picture seems dominated by stark light and dark tones.
Density units
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