User's Guide

60 | NEC SPECTRAVIEW II - USER’S GUIDE
Color Separation – The separating of a color image into the cyan, magenta, yellow, and black
color layers used for printing.
Color Separation Tables – A set of conversion tables used to calculate the separating of RGB im-
ages into the CMYK layers necessary for printing.
Color Space – A three dimensional representation of colors. Examples are RGB, CIE xyY, and
CIE Lab.
ColorSync – The Color Management System built into the Macintosh Operating System (Mac
OS).
Color Temperature – The color of light given off by an object, known as a blackbody, as it is
heated to a given temperature in degrees Kelvin. Low color temperatures such as 5000K are red-
dish, whilst higher color temperatures such as 9300K are bluish. A color temperature of 6500K is
considered to be “neutral” white.
Contrast Ratio – The ratio of the white luminance (Intensity) and black luminance (Black Level) of
the display.
Correlated Color Temperature – The closest matching color, expressed in Kelvin, of a white
point that does not lie exactly on the blackbody locus.
CMYK – The subtractive colors used in printing: Cyan, Magenta, Yellow, and Black. Note that
Black is referred to using “K” to avoid confusion with “blue”.
D Illuminants – CIE Daylight Standard Illuminants based on approximating daylight. The sub-
script denotes the correlated color temperature of the illuminant. For example, D50 has a corre-
lated color temperature of 5000K.
Delta-E (Δ-E) – A measurement of how different two colors are to each other. In SpectraView, Del-
ta-E values are derived by calculating the distance between two colors in Lab color space using
the CIE 94 formula. A Delta-E value of 1 indicates a just perceptual difference between two colors.
Delta-uv (Δ-uv) – A measure of how different two colors are, irrespective of luminance. In Spec-
traView Delta-uv values are used to indicate how far a white point is from the blackbody locus. CIE
uv color space is used instead of CIE xy because it is more perceptually uniform or linear.
Device Dependent Color – A color space that is tied to the color rendering capabilities of a spe-
cic device. Examples are RGB color spaces that depend on the phosphor or lter colors used on
the display. Another example is CMYK color spaces that are dependent on the types of inks and
paper used.
Device Gamut – The range of colors that a device can produce.
Device Independent Color – A color space that can describe color independently of the capabili-
ties of a specic device. An example is the CIE xy color space.
DDC/CI – Display Data Channel Command Interface is a two-way communications link between
the video graphics adapter and display monitor using the video signal cable.
DICOM – Digital Imaging and Communications in Medicine.
Foot Lamberts (fL) – A unit of luminance. One foot Lambert is equal to 1 Candela per meter
squared divided by 10.76/π (approximately 3.43) .