Adobe Monitor Setup.
see AMS.

Aliasage
Phenomenon which makes the pixels visible, in particular on the level of the diagonals and the curves, their giving the aspect of a crênelage. One speaks about the effect of staircase. Contours are not smooth any more but appear in teeth of saw.

AMS
Characterization of color file for monitor used by the color management system of Adobe Photoshop software.

ANSI
American National Standards Institute. American national institute of the standards.

Analog to digital converter
Component of a scanner. Converts the analogical electric signals into exploitable numerical signals by a computer.

Autocorrection of the tonalities.
One of the automatic functions of the majority of the scanners or the software. If, at the time of the analysis of the original document, a nonuniform distribution of the pixels is noted, the apparatus carries out a widening of the range of the tonalities in order to optimize the image.

Automatisms
Automatic functions carried out by the scanner or the software, for example:
Distortion of the curve of gradation
Correction of the range of the tonalities

Bit
Smaller unit of information.
Basic unit for all the operations carried out by a computer. Comparable with a switch knowing only two states: High or low, that is to say 1 or 0.

Bitmap
Digitial image made up of many small squares called pixels.

Black Body.
Theoretical object absorbing the totality of incidental radiations. So the light emitted since a black body comes only from him and was not considered.

Brightness
Measure intensity (brightness) of a source of light, generally expressed in Candelas per square meter (Cdm2) or feet Lamberts.

Calibration
Process consists of syntonizing all the components of the system like the monitor, the scanner and the printer.

Candelas (cd)
International unit of measurement of the light intensity. Brightness can be expressed in Candelas per square meter (Cdm2).

Cathode ray Tube
to see CRT

CCD Sensor
Charge-coupled device. Component of any flat scanner; essential for the transformation of the signal. It is here that the conversion of the light signals into electric signals takes place.

Chromatic model
System allowing to describe the colors. Examples: RGB, CMYK, CIELAB, CIELUV.

Chromatic profile
It acts of a standardized profile used to define the colour spaces of the equipment of seizure, of representation and exit, i.e. the scanner, the monitor and the printer.

CIE
Commission internationale de l'Eclairage the commission has the role of defining standards for the color and lighting and worked out the chromatic system standardized XYZ of the CIE in 1931 and the chromatic system Lab.

CIELAB
Space chromatic standardized in three dimensions worked out by the Co in 1976. "L *" represents the luminosity, "A *" represents the co-ordinate of the color on the axis Rouge/Green and "B *" represent the co-ordinate of the color on the axis Jaune/Blue. Lab space (as it is often called) is linear according to perception, this fact two colors close one to the other have close co-ordinates numerically.
L*: variable of clearness
L*= 116 [Y/Yn]1/3 - 16
A * and B *: co-ordinates of chromaticity:
a* = 500 [(X/Xn)1/3- (Y/Yn)1/3]
b* = 500 [(Y/Yn)1/3 - (Z/Zn)1/3]

CIE-L*u*v*
Colorimetric space relative to a reference of white created in 1976. CIE-L*u*v space * is linear according to perception, this fact two colors close one to the other have close co-ordinates numerically.

CIE-uv (coordonnées chromatiques)
Co-ordinates of a color in colorimetric space CIE-L*u*v *.
?E*uv = v[(?L*)2 + (?u*)2 + (?v*)2 ]

CIE-xy (coordonnées chromatiques)
Co-ordinates of a color in colorimetric space CIE-xyY.

CIE xyY
Standard independent colorimetric space very much used. "Y" represents Brightness, "X" and "there" represent the co-ordinates of the color considered.

CMYK
Basic colors for the impression in quadrichromy: cyan magenta, yellow and black. You will find sometimes abbreviation English CMYK (Cyan, Magenta, Yellow, Black)

CMS
Abbreviation of Color System Management. Software used to manage the color at the time of the passage of elements of the numerical chain of image processing to another (scanner, monitor, imprimante').

Coefficient of enlarging
This coefficient indicates in which proportions the original must be increased on the image posted on computer. From a mathematical point of view, this coefficient is obtained by dividing the format of exit by the initial format. If one increases an original of format 3 X 3 cm with a format of 9 X 9 cm, the coefficient of enlarging will be 3 (that is to say 300 %).

Colorimeter
Apparatus optronic (optical and electronic) of measurement of the color by the analysis of the light emitted or reflected according to three channels Red, Green and Blue (sometimes more).

Colorimetric space
This known as of a system of representation of the color according to several dimensions. Colorimetric spaces are often three-dimensional (like spaces RVB, CIE-xyY or CIE-L*a*b * for example).

Color Management System
see CMS.

ColorSync
System of management of the color developed for the APPLE computer.

Commission internationale de l'Eclairage.
see CIE.

CRD
Color Rendering Dictionary (Dictionary of returned colors). Used especially in RIP.

CRT
Abbreviation of Ray Cathode Tubes. Tube glass forming the screen of posting of the monitors. An electron beam irradiates phosphorus covering the interior of the tube to emit light and to form an image.

D50 Daylight.
It is a term to identify a source of light which emits with a temperature of color of 5000 Kelvin degrees.

darkest zone
On an original document, it acts of the zone darkest (but not necessarily black) having to be
reproduced, and often that having the highest density.

DE
Value translating the variation of perception between two colors and allowing to define how much these colors are close or distant. OF is given by calculating the distance which separates two colors in colorimetric space CIE-L*u*v *. One FROM 1 indicates the beginning of a difference in perception
between two coleurs.

Density
The degree of impermeability of layer of color to the light. Mathematically speaking, it acts of the logarithm of opacity. Concept of opacity and density.

Depth of bits
The number of bits describing defines a pixel. Determine the number of levels of gray which can be represented. Colorimetric representation of the space of a lumieuse source. There are several methods to describe numeriquement a source of light (then also a screen). It include the co-ordinates xy, co-ordinates UV of space Co 1960 UCS, the co-ordinates u*v * of space Co 1976 UCS, the temperature of color. Space CIELUV is sometimes used. Like it calls upon a point of origin, it is imperative to determine before the standard light before use of this system.

Detramage
Technique used in order to avoid the effects of watered effect. The woven documents are analyzed by a sampling apart from the zone of clearness of the scanner what makes them fuzzy. The re-establishment of the clearness of the image is then automatically carried out on computer.

Device-dependent
This known as of a colorimetric space on which returned color is dependent on a given element (like a peripheral for example). Colorimetric space RVB, for example, is depending amongst other things on the characteristics of the phosphorus used by the monitor. Colorimetric space CMJN is depend inter alia characteristics on the inks and paper used for the impression.

Device-independent
This known as of a colorimetric space able to return account of a color whatever the characteristics of the elements of the numerical chain of image processing. CIE-xyY space makes of it in particular party.

Dispersed light
On images where clear zones and dark zones are côtoient, it may be that the light reflected by certain clear points is dispersed and detected by sensors CCC neighbors. These points thus adopt by error a too clear value. The digitized result is then faded. In the case of scanners flat, where digitalization is carried out line not line, this risk is greater than in the case of drum scanners where the original document is digitized point by point.

Digital camera
Apparatus with special back panel on which CCD sensors are laid out in the form of a matrix. It thus allows a direct digitalization of bulky objects in three dimensions, adapted for a scanner.

Digitalization
itself with all the final adjustments.

Distortion of the gradation
The scanner can proceed to a distortion of the curve of gradation in order to adapt the image in RVB to the perception of our eye.

Document with dominant of color
Document presenting any balancing of the colors or a predominance of a certain color, like the old yellowed photographs or the stereotypes of sun couchers.

Document with flutters
Original document on which one can observe small reflexions which form clear surfaces (or flutters), as on glasses of glasses or on the surface of water points. One finds sometimes the term English "Catchlight".

Document with the feature
These documents exclusively contain black or white pixels and any level of gray nor of colors. The text that you are reading is thus also a document with the feature.

Document color
Image color represented for example in the form of slide or of photo stereotype.

Document in levels of gray
Called in general image in black and white. All the colors are represented in the form of différenteséchelles of gray.

Document test IT8
Document color standardized intended for the calibration of the scanner. Calibration of the system

Document High Key
Image which, from the reason represented, very clear and is contrasted little, like a polar polar bear in snow for example.

Document Low Key
Image which, from the reason represented, very dark and is contrasted little, and of weak range of tonalities, like a black plate on a tablecloth dark blue for example.

dpi
Of English Dowries per Inch (points per inch or PPP) Measuring unit of the resolution of a peripheral of exit, like a printer or flasheuse. Also used to indicate the resolution of digitalization. The metric unit dpcm (Dowries per centimeter/points per centimetre) only is seldom used. The scanners of good quality enable you to choose between these two units. 1 dpi = 1 dpcm X 2,54

Duv
Value translating the variation of perception between two colors independently of Brightness. Duv is used to determine how much a white point is near or not to the curve of the places of the black bodies. Coordonées CIE-UV are preferred in coordonées CIE-xy because they are linear compared to perception.

Effect of mottled
(in English Speckling) Just like the effect of clouded, this phenomenon is noted when y has an excessive stressing of the clearness of the original document. The most negligible irregularities of the image become visible, or one can observe clear pixels isolated in dark zones, phenomenon resulting from the generation of noise.

EPS
of English Encapsulated Post-script Format of file used in the sector of the CAM. A file EPS is composed of a main file comprising of the summary data of visualization of the image and distinct files containing the detailed data for each extract of color.

Effect of clouded
(in English Mottling) appearing Effect on all surface of the image and often generated by a stressing of clearness. Various pixels, even the grain of film, are made visible.

Effect of halation
It can be obtained by an excessive reinforcement of clearness. Halations are formed around the zones with flutters. Clear surfaces are thus extended and there is less of details represented on the image.

Effect of watered effect
Occurs at the time of the digitalization of woven documents. It is generated by superposition of various screens, as the screen of analysis of the scanner by sampling and the screen of impression of the original document for example. Results in the observation of lines or small stars on the image. The image takes the structure of fabric, as if it were woven.

Factor of tramage
Parameter included in the calculation of the resolution of digitalization in order to optimize the result, when the digitized image is intended for an impression with screen. To obtain a raised quality, the factor of tramage should always be of 2.

Feet Lamberts (fL)
Measuring unit of Brightness. Not Blanc usually Definite the white purest that a monitor can post. The color of this white point is expressed by the value of temperature of color.

Final digitalization
Last phase of digitalization after the digitalization of overall picture and the prenumerisation.

Gradation/ Gamma
Indicate the relation, at the time of the handling of an image, between the values of entry and the values of exit. In the case of a standard adjustment, the value of entry is equal to the value of exit.

ICC ' Abbreviation of International Color Consortium. Group resulting from
the industry of the color developing of the standards for technologies of management of the color.

Influence temperature
A scanner, a screen, a printer will be different according to their temperature. It is nécesaire to let heat the machines before gauging them or caracteriser. Sometimes, losque the temperature of a product varies, its color changes. This phenomenon apelle thermochromism. To increase the precision of measurements, or of the reproduction, it is necessary to carry out them in a part at constant temperature after the product was also stabilized with tempèrature of the part. It is necessary to pay attention with charters IT8, if the scanner has a high temperature. In this case, it fauf to pay attention not to leave the charter too a long time in the scanner.

Interpolation
Process which consists in increasing the resolution beyond the maximum physical resolution of the scanner and which makes it possible to carry out greater enlargings. New pixels are added to the existing pixels. Their chromatic value is calculated according to the neighbouring pixels.

Kelvin
Scale of absolute temperature based on the absolute zero (0° Kelvin) correspondent with ' 273° Centigrade Lab ' to see CIE-L*a*b *. Place of the black bodies ' Curves formed by the whole of the points relating to the color emitted by a black body has various temperatures. Lines of Isotempérature Lignes represented in a diagram color (as CIE-UV) is which represents the whole of the white points whose color seems visually equal to that emitted by a black body. Outline of screen Indicates, at the time of the impression, the number of lines of screen in a given zone. This zone can be expressed is in lines per inch (lpi = lines per inch), maybe in lines per centimetre (lpcm), but more rarely. A screen of 60 corresponds to 60 lines of screen on one centimetre (60 lpcm), what is equivalent to a screen of 150 in lines per inch (1 inch = 2,54 cm). More the lines are tightened, better will be the quality of the impression, but it will be all the more difficult to control it.

Look Up Table
to see LUTE

lpi
Of English lines per inch (lines per inch) Measuring unit of the resolution of the image at exit. In this case, it is indicated the number of lines which the image in a given zone comprises (on 1 inch) (or 1 centimetre, one speaks then about lpcm or lines per centimetre, but this measuring unit is more rarely used).

LUT
(Look up table) Table of correspondence enters of the values of entry and exit used mainly the video charts.

Maximum Overprint
which indicates the maximum sum of the 4 colors in impression CMYK. "maximum covering of surface"

Meter of screens.
Used to measure the outline of screen. The meter of screens is posed on the original document.
The outline of required screen is located in the zone where one notes an effect of watered effect.

Noise
It is not a question of the noise which the scanner makes. It is defined as the electric disturbances thus being able to result in an inaccurate reading of certain pixels.

Opacity
Degree of impermeability of layer of color to the light. Opacity is calculated by dividing the intensity of the light projected by the volume of light which the original document reflects or lets cross.

Opaque document
Document which reflects the projected light, like a photograph or a newspaper cutting for example.

Patch
Square of color (printed paper form by the printer, read by the scanner, posted by the screen), who contains a color of reference which is measured and then compared with the value of reference.

Phosphorus
Materials which emits light as it is bombarded by a radiation a certain wavelength. The CRT contain three type of phosphorus laid out on surface of the screen which emit of the Rouge light, Green and Blue.

Proof Software.
Prévisualisation on a monitor of returned which an image will have on
a system of impression

Point of screen
Point elementary at the time of the process of the impression. A point of screen consists of several points of the image, those being able to be only black or white. More the point of screen must be dark, more there will be blackened points of image.

Postérisation
Phenomenon consisting in widening the range of the tonalities. The tone dark are obscured more still, and the tone lights cleared up simultaneously, making disappear certain levels from gray. The histogram corresponding to this image presents gaps, there is a break in the transition the tone. Contrasts with the image are widened being able to make disappear certain details.

Profile ICC
File Profile respecting the standard defined by International Color Consortium (ICC).

Range of tonalities
For each original document, it is possible to work out a histogram on which 256 bars are deferred corresponding to the various tonalities of gray. The height of the bar indicates the number of pixels adopting this tonality of gray. The distribution of the bars, the dark one with light, indicate the range of the tonalities of the document. By way of example, a document High Key will present a very restricted range of tonalities since practically all the pixels will be located in the clear zone.

Resolution of digitalization
Indicate the number of different samplings having to be carried out to analyze a given zone. It is measured in dpi (of English dowries per inchs/ points per inch often indicated "PPP") or in dpcm (of English dowries per centimeter/ points per centimetre), this metric unit being however employed only very seldom. In general, more the resolution of digitalization is raised, better will be the quality of the image posted on the computer.

RGB
Red, green and blue. Primary colors of a monitor or a scanner. If each color is present at 100 %, a white light is obtained. You will find sometimes abbreviation English RGB (Red, Green, Blue).

Saturation.
Expression of the purity of a color compared to a of the same gray
luminosity. For example a sharp red is a saturated color, a pink is in fact a désaturé red, and a white has a saturation null drum Scanner With this type of
scanner, the documents are placed on a cylinder and are analyzed by sampling
point by point.

Spectrocolorimeter.
Apparatus allowing to measure the components of a color. The spectrophotometer splits up each color in its chromatic components
which can then have left individually with the values measurement
CIELAB, for example. Additive synthesis of the colors Recombining of a color by the
addition of several coloured sources of light. It is the principle of operation of the monitors which créentle white
by addition of Rouge light, Green and Blue emitted by phosphorus

Standard document
Original document which does not present any characteristic (what does not want to say ordinary or banal). One finds them in the form of slides or of photo stereotypes, and their distribution of the tonalities is uniform. They are consequently easy to digitize, generally automatically.

Stressing of clearness
Process also called as "vague masking" (in English Unsharp masking - USM). It is a technical process allowing the development of the original document by accentuating the clearness of contours on the image.

Subtractive synthesis of the colors.
Recombining of a color by the subtraction of a part of the light of
illumination. It is the principle of operation of the printers which create the
black by the subtraction of Rouge light (captured by Cyan ink), Green (captured by Magenta ink) and Blue (captured by Yellow ink). Noir ink is used in complement to increase the suppression of Surexposé light, under exposed original Document which, not because of its reasons but because of a technical defect, is too dark (under-exposed) or too clearly (over-exposed).

Temperature of Color
Color of the light emitted by a black body when it is brought up to a given temperature (expressed in Kelvin degree) Temperature of Color in Température correlation of color expressed nearest in Kelvin degrees for a white point which is not exactly on the curve of place of the black bodies

Tiff
Abbreviation of the English denomination Tagged Image Spins Format. The format of image most used and supported by all the usual systems. This format is thus particularly suitable for the data exchange.

Tonal Curve
Graph representing the relation between the values of entry and exit of a system or a given peripheral. This graph can in particular represent the correspondence between the values of a colorexpressed in a software in RVB and the luminous result on the surface of the screen.

Total Ink limit
to see: Overprint Maximum

Transparent document
Document which lets cross the light, like the slides or the negative ones.

Tube photomultiplier
Component of a drum scanner in which the light signal which penetrates there is converted into an amplified electric signal then.

Variation of density
Corresponds to the difference between the highest level of density and the lowest level of the density of a document. For the opaque documents, it is in general about 2,0 D and of 3,0 D or more for the transparent documents.

Woven document
Original document in levels of gray or color presented in printed form and thus woven.

Zone of high lights
On an original document, it acts of the zone most luminous (but not necessarily white) having to be reproduced and presenting