GLOSSARY OF TERMS
Absolute Colorimetric Rendering Intent
Absolute Colorimetric Rendering Intent is the same as Relative Colorimetric, but where the white point is mapped. This usually means that the paper white has ink put on it to make it match the paper white of the input profile.
Calibrate
To calibrate is to adjust the graduations of a machine to match a standard. It may also refer to the creation of that standard.
CIE LAB
A device-independent color space derived from CIE 1931 XYZ color space and calculated using cube roots. LAB (L*a*b*) is perceptually linear. An ICC Profile consists of two tables that allow the translation of color from the device’s color space in to and out of LAB color space.
CMYK
CMYK stands for Cyan, Magenta, Yellow, and Black – the subtractive color primaries.
Densitometer
A densitometer is a device that measures the degree of darkness or color saturation of a material.
DPI or Dots Per Inch
DPI is a measure of the number of addressable dots (specified points) that a printer can put on a paper.
G7
G7™ is a new calibration method developed to support the GRACoL 7 specification. The 'G' refers to calibrating Gray values, while the '7' refers to the seven primary color values defined in the ISO 12647-2 printing standard: Cyan, Magenta, Yellow, Black (K), Red (M+Y), Green (C+Y) and Blue (C+M). Although originally intended for commercial offset printing, the G7 method is applicable to virtually any CMYK imaging process, and has been successfully tested on a wide range of processes, including coated and uncoated offset, newsprint, gravure, flexography, dye-sublimation, ink-jet, and electrophotography, as well as a wide range of AM and FM screening methods.
New Vision's color specialists are G7 certified GRACoL Expert Consultants and have completed an IDE Alliance certification program. They are among an elite group of professionals who are experts in the new GRACoL press calibration process. For more information, read our GRACoL 7 Certification document.
Gamut
Gamut is the range of colors that a given device can render. It is often expressed as a graph in 3-dimensional space.
ICC Profile
According to the International Color Consortium website, the ICC committee was founded by 8 graphics industry vendors for the purpose of creating, promoting, and encouraging the standardization and evolution of an open, vendor-neutral, cross-platform color management system and components. Simply put, an ICC Profile is used for color communication between the devices in the workflow and is a mathematical description of the way a given machine renders color for a given configuration. An ICC Profile has tables in it that are used for converting color into and out of the color space that the ICC Profile represents.
Ink Limit/Restriction
A limit placed on the amount of a given ink is referred to as an ink limit or restriction. This is usually done in a RIP.
Perceptual Rendering Intent (also known as Photographic Rendering Intent)
A rendering intent where the relationship of the colors is kept when bringing out of gamut colors in to gamut. This has the effect of changing the colors that are in gamut but keeps detail in the out of gamut colors.
PPI or Pixels Per Inch
PPI is a measure of the number of addressable points in a file. There is not necessarily a relationship between the PPI of a file and the DPI of which it is printed.
Relative Colorimetric Rendering Intent
A relative colorimetric rendering intent is when all in gamut colors are not changed and out of gamut colors are mapped to the nearest in gamut color. With relative colorimetric rendering intent, the white point is not adjusted.
Rendering Intent
The Rendering Intent determines how a Color Management Module (CMM) maps colors from one color space to another. The four ICC recognized rendering intents are Absolute Colorimetric, Perceptual, Relative Colorimetric, and Saturation.
RGB
RGB stands for Red, Green, and Blue – the additive color primaries. Devices that work in RGB include capture devices (digital cameras, scanners), displays (CRTs, LCDs), and some printers (Durst Lambda, some ink jet printers when used with their drivers).
RIP
Raster Image Processor
Saturation Rendering Intent
A saturation rendering intent occurs where color fidelity is sacrificed for keeping colors as saturated as possible. Each color is mapped without consideration of any other colors.
Spectrophotometer
A spectrophotometer is a device that samples light in the visible region (400 – 700 nm) that is reflecting or being passed through a given material. In the creation of ICC Profiles, these are used to measure color output from a given device.
Total Ink Limit
Total Ink Limit is a limit placed on the total amount of ink that a printer can put in an addressable spot on a page. In CMYK printers, there is a total of 400% possible (100% each of Cyan, Magenta, Yellow and Black). The total ink limit usually falls below this.
