A
a*
Red - green coordinate in CIE L*a*b* color space. A positive a* value indicates redness and a negative a* value indicates greenness.
Absolute Colorimetric Rendering Intent
A rendering intent that preserves in-gamut colors and clips those that are out-of-gamut. This method preserves the white point, which may sound appealing, but may actually result in image color shifts. Absolute colorimetric is most commonly used for proofing and is rarely used by photographers.
Absolute White
In theory, a material that perfectly reflects all light energy at every visible wavelength. In practice, a solid white with known spectral reflectance data that is used as the reference white for all measurements of absolute reflectance. When calibrating a spectrophotometer, often a white ceramic plaque is measured and used as the absolute white reference.
Absorb (Absorption)
Dissipation of the energy of electromagnetic waves into other forms (e.g., heat) as a result of its interaction with matter; a decrease in directional transmittance of incident radiation, resulting in a modification or conversion of the absorbed energy.
Absorbance
“Light-stopping ability.” The higher the value, the more light the sample absorbs. Values typically range from 0 to 3.0. Mathematically, absorbance is calculated A = log10(1/T) where T is transmittance, expressed as a decimal from 0 to 1 (for example, 0.5R is 50%R). This is the same equation used to calculate density in graphic arts and photography applications.
Achromatic Color
Light without color, which produces a neutral white, gray, or black color that does not have a hue.
Adaptation
The ability of the eye to adjust to different light sources or light levels. This allows the visual system to adjust its sensitivity to different lighting conditions.
Additive Color
The sum of primary colors to produce a multitude of colors. The most commonly used additive color model is RGB (red, green, blue), which is used by computer monitors to produce their display and scanners and digital cameras to capture images.
Additive Color Mixture
Mixing of the three primary color lights (Red, Green and Blue) to obtain colors. For example, Green + Red = Yellow, Red + Blue = Magenta, and Blue + Green = Cyan.
Additive Primaries
Red, Green, and Blue light. Combining all three additive primaries at 100% intensity produces white light. Combined them at varying intensities produces a gamut of different colors. Combining two primaries at 100% produces a subtractive primary: 100% Red + 100% Green = Yellow, 100% Red + 100% Blue = Magenta, 100% Green + 100% Blue = Cyan.
Addressable Resolution
The maximum resolution of any device.
Adobe® Acrobat®
Adobe’s software application used to create and view Portable Document Format (PDF) files. PDF files allow others to view a document exactly as it was designed without having the software or fonts used to create the file.
Adobe® Creative Suite®
A collection of graphic design, video editing, and web development applications made by Adobe Systems, including Photoshop®, Illustrator®, Acrobat®, InDesign®, and the Bridge for managing all loaded Creative Suite applications.
Airbrush
A software tool found in image editing programs that simulates the effect of a mechanical airbrush.
Aliasing
The visual stair stepping of edges that occurs in an image with low resolution and can be caused by improper image sampling or processing. Also called “jagging".
Ambient Light
The available light in a room, natural or mechanical. Ambient light plays a role in how colors are displayed on screen and in print, and should be considered when judging color.
American National Standards Institute (ANSI)
A federal organization responsible for standardizing computer systems for trade and communications purposes. COBOL, FORTRAN, and C programming languages are all ANSI standards.
Angle of Incidence
The angle at which a beam of light strikes the surface of an object compared to the perpendicular to the object surface.
Angle of Reflection
The angle at which a beam of light is reflected from the surface of an object compared to the perpendicular to the object surface.
Angle of View
The angle at which a sample is viewed compared to the perpendicular to the surface.
Anti-Aliasing
Removing or softening jagged (aliased) edges using averaging or blending techniques.
Anti Set Off Spray
A starch powder that is sprayed on freshly printed sheets to prevent smudging or transferring wet ink to the underside of a sheet on top.
Apparent Color Temperature
The color appearance of a light source related to the absolute color temperature of a black body radiator having the same color.
Appearance
Manifestation of the nature of objects and materials through visual attributes such as size, shape, color, texture, glossiness, transparency, opacity, etc.
Apple ColorSync
A platform-independent color management system from Apple that provides essential services for fast, consistent, accurate color calibration, proofing, and reproduction using input, output, and display devices. ColorSync also provides an interface for system-wide color management settings that allows users to save color settings for specific jobs and switch between settings.
Artifact
In digital graphics applications, unwanted visual anomalies or defects generated by an input or output device or software operation that degrades image quality.
Artificial Daylight
Term loosely applied to light sources, frequently equipped with filters, that try to reproduce the color and spectral distribution of daylight. A more specific definition of the light source is preferred.
ASCII (American Standard Code for Information Interchange)
A computer coding system that converts letters, numbers, and symbols to binary values that a computer can understand.
Aspect Ratio
The relationship of the horizontal and vertical measures of an image. The horizontal value is placed first (i.e. 3:2).
Attribute
A distinguishing characteristic of a sensation, perception or mode of appearance. Colors are often described by their attributes of hue, chroma (or saturation) and lightness.
B
b*
Yellow - blue coordinate in CIE L*a*b* color space. A positive b* value indicates yellowness and a negative b* value indicates blueness.
Banding
Inaccurate color representation that results in patterned stripes created by harsh, well-defined transitions between different ranges. Banding is generally caused by insufficient color or gray-scale ranges within the output device's image processor, or by insufficient information within the original scan.
Bandwidth
A network or data connection’s capacity for carrying data. The larger the bandwidth number, the faster the digital transmission. For analog transmission, bandwidth is measured in cycles per second or hertz (Hz). For digital transmission, bandwidth is measured in bits per second (bps).
Beer’s Law
Describes the mathematical relationship between the absorption of light energy relative to the concentration of a dye or pigment.
Bit Depth
The number of bits used to define the shade or color of each pixel in an image. A 1-bit image is black and white, an 8-bit grayscale image provides 256 shades of gray, an 8-bit color image provides 256 colors, and a 24-bit image provides over 16 million colors (8 bits for red, 8 for blue, and 8 for green).
Bitmap (BMP)
An image file format that is formed by a rectangular grid of pixels or dots, most commonly used on Microsoft Windows and OS/2 operating systems. This file format is supported by various applications and uses RLE lossless compression.
Bits per Pixel (bpp)
The number of bits used to describe the color or intensity of a pixel. For example, using 8 bits to store a value from the RGB color model would permit 3 bits to be used for both red and green values and 2 bits for the blue value. Blue gets a smaller range because the human eye contains less blue cones and is thus is less sensitive to blue variations.
Bits per Second (bps)
A measurement of data transmission speeds that represents the number of bits that pass a certain point in one second.
Black
The color that is produced when an object absorbs all wavelengths from the light source.
Black Body (Planckian) Locus
The set of points on a chromaticity diagram representing the colors of perfect radiators having various color temperatures.
Black Body Radiator
In theory, an object that absorbs all energy that comes into contact with it.
Black Generation
Adding Black ink to the other process colors (Cyan, Magenta and Yellow) when printing an image. Black generation is typically handled with gray component removal (GCR) or under color removal (UCR).
Black Point
The darkest shadow in an image’s histogram, with a value of 0, 0, 0. Black point can be used to adjust the tonal range of the image. Ideally, the black point is 0% neutral reflectance or transmittance.
Blanket
A canvas and rubber assembly that covers the cylinder of an offset press, used to transfer the ink from the plate to the paper.
Blanket Bar
An accessory on an offset press that helps retain the blanket cylinder.
Blanket Cylinder
The cylinder that transfers the printing areas of the plate to the paper on an offset press.
Bleed
An image or inked area that extends beyond the trimmed edge of a page.
Blooming
A visual effect caused by overexposing an image sensor to too much light, resulting in a leakage into adjacent photo sites. This “digital overexposure” can cause distortions of the subject and/or color.
Blur
Softening an image’s detail.
Bon-a-tirer or BAT (bone-ah-ti-ray)
A proof accepted by the artist that is used as the standard for comparing all subsequent prints. Some printers require a signed BAT before production printing can begin.
Bounding Box
In graphics applications, the smallest regular shaped box that encloses an object, usually rectangular in shape.
Brightness
The overall intensity of an image. The lower the brightness value, the darker the image; the higher the value, the lighter the image.
Bronzing
A problem that can occur with certain ink/paper combinations where darkened, or "bronzed," reflections from inked areas are juxtaposed with areas”.
C
C*
Chromaticity coordinate in CIE L*C*h color space. A chroma of 0 (zero) indicates a perfectly neutral color, while a larger C* value indicates a more chromatic (saturated) color.
Cache
A bank of high-speed memory set aside for frequently accessed data.
Calibration
The second step in the color management process, calibration adjusts a device to its known specifications to help compensate for color “drift” over time. Calibration must be performed for devices whose color characteristics change frequently, such as monitors because phosphors lose brightness over time, and printers because output can change with different inks and media.
Calibration Bars
A strip of color or tonal patches used to check the quality of a negative, proof, or printed piece, or measured into calibration software to help bring a printing device back to known standards.
Camera Profile
Defines how the raw image is rendered by image processing software. Profiles contain a definition of exactly what the color of a particular pixel should be, relative to the raw data in the original image. You can adjust how your editing software interprets the color from your camera by using the controls in the Camera Calibration panel and saving the changes as a preset.
Camera-Ready Art
Any artwork or type that is ready to be submitted for prepress and printing.
Candela per square metre (cd/m2)
A unit of luminance based on the candela, the international unit of luminous intensity, and the square metre of the area. Most consumer desktop LCDs have a luminance of 200 to 300 cd/m2.
Capture
Acquiring digital image information with an input device, such as a scanner or digital camera.
Channel
A component of a digital image that carries data for one color layer. A grayscale image has one color channel, an RGB image has three color channels, and a CMYK image has four color channels. When all channels are combined, a full-color image is created.
Characterization
The third step in the color management process, characterization is measuring the device’s actual RGB or CMYK color values with a colorimeter or spectrophotometer to determine its color reproduction characteristics.
Chroma
Attribute of color used in the Munsell Color System to indicate the degree of departure from a gray of the same value. Correlates with dimension of saturation; the farther from the axis, the purer the color.
Chromatic
A color that is perceived to have a hue, not white, gray or black.
Chromaticity
The quality of a color, independent of brightness.
Chromaticity Diagram
In practical terms, a two-dimensional graph on which a color may be plotted ac- cording to its hue and chroma. The third dimension of this graph is the luminance factor, or lightness, which is independent of hue or chroma. The location of a point on this graph indicates roughly what color it is (red, green, blue, purple, and so forth) and how saturated it appears. This information must be interpreted with caution, since the coordinates of neutral colors differ with each illuminant. The coordinates can rarely be interpreted with appearance unless the illuminant is specified. A plot of all colors has a characteristic horseshoe shape.
Clipboard
An area of memory used to temporarily store selection pixels that is accessed using the cut, copy, and paste commands.
CIE (International Commission on Illumination)
The International Commission on Illumination (usually abbreviated CIE for its French name, Commission Internationale de l’Eclairage) is the international authority on light, illumination, color, and color spaces. It was established in 1913 as a successor to the Commission Internationale de Photométrie and is today based in Vienna, Austria.
CIE Colorimetry
The measurement of color according to the spectral responsiveness of a CIE standard observer.
CIELab (CIELAB, L*a*b*)
A uniform (opponent color scale) color space in which colors are located within a three-dimensional rectangular coordinate system; the three dimensions are lightness (L*), redness/greenness (a*) and yellowness/blueness (b*). CIELab is part of the current CIE recommendations. A uniform color space utilizing an Adams Nickerson cube root formula, adopted by the CIE in 1976 for use in the measurement of small color differences. Pronounced “see-lab” and also referred to as L*a*b* (pronounced, “el-star”, “ay-star”, “bee-star”).
CIE Standard Illuminants
The CIE characterized several standard illuminants, designated as “A”, “B”, “C” and “D”, and published standards spectral power distribution curves to characterize the color of light for each. Illuminant A is designed to simulate incandescent light from light bulbs. Illuminant D is designed to simulate natural lighting of two different spectral distributions. D50 represents light at 5000K, and D65 represents 6500K light. Graphic arts standard viewing conditions specify white light at 5000K.
CIE Standard Observer
The observer data for a 2 degree field of view, adopted by the CIE in 1931 to represent the response of the average human eye, when adapted to an equal energy spectrum. A supplementary 10 degree observer was adopted in 1964.
CIE Tristimulus Values
Amounts of the three components necessary in a three-color additive mixture required for matching a color: in the CIE System, they are designated as X, Y, and Z. The illuminant and standard observer color matching functions used must be designated; if they are not, the assumption is made that the values are for the 1931 CIE 2 Standard Observer and Illuminant C.
CIELCh
A uniform (opponent color scale) color space in which colors are located within a three-dimensional polar coordinate system; the three dimensions are lightness (L*), chroma (C*), and hue angle (h). CIELCh is part of the current CIE recommendations. To pronounce CIELCh, just say the letters.
CIE xy Chromaticity Diagram
A two-dimensional graph of the chromaticity coordinates, x as the abscissa and y as the ordinate, which shows the spectrum locus (chromaticity coordinates of mono-chromatic light, 380-770nm). It has many useful properties for comparing colors of both luminous and non-luminous materials.
Clipping
An effect that occurs when all values lighter than a specific tone are converted to white, and all values darker are converted to black. Clipping can be caused by too little contrast; when certain gray scale values are lost or compressed either into the range of pure white or pure black.
CMC
Also CMC (l:c). A color difference formula based on the CIELCh (opponent color scale) color space, in which equivalent total color difference values represent equivalent visual differences, regardless of the color.
CMYK (Cyan, Magenta, Yellow, Key (Black))
The three primary colors of the subtractive color model, used in color printing. In theory, the combination of pure CMY inks produces Black; in reality, Black must be added to produce a full color gamut.
CMYK Printer
A printer that uses Cyan, Magenta, Yellow and Black to reproduce images on media. Most printers that operate with a Post-Script RIP are CMYK printers, meaning the RIP can accept RGB, LAB or CMYK input data and convert it to CMYK for output to the print engine.
Coating
The process of treating a media or substrate to accept inkjet inks. Also, a thin covering that provides protection from UV-induced fading, smudging and fingerprints, which may or may not improve the permanence of the print because most fading is due to visible light.
Cockling
The wavy or wrinkled appearance of paper when ink absorption limits have been exceeded, or a printing defect typically seen as deforming wrinkles on paper and usually caused by heavy ink loads or moisture.
Color
Visual perception created when light of varying wavelengths in the region of approximately 400 –700 nm is detected by the receptors of the eye and processed by the brain.
Color Adjustment
In a printing process, an adjustment of an initial color according to the determined standard; should be checked regularly because it can change frequently.
Color Aptitude
The ability to work with and understand color; includes both inherited skills and work experience.
Color Attribute
A three-dimensional characteristic of the appearance of an object. One dimension usually defines the lightness, the other two together define the chromaticity.
Color Balance
The ability to reproduce all of the colors in a scene within an acceptable standard.
Color Calibration
Using software and/or hardware to adjust and coordinate colors between two or more digital devices. Color calibration systems commonly compare device color profiles and translate one color model into a device-independent language.
Color Cast
An unwanted tint of one color in an image that can be caused by an input device, output device, or lighting conditions.
Color Compression
Shrinking the color gamut of an original to the color gamut a device can represent or reproduce.
Color Constancy
Relative independence of perceived object color to changes in color of the light source.
Color Correction
Adjusting an image to correct for color imbalances or for the characteristics of the chosen output device.
Color Curve
A graph that displays color measurements and can be used to make color changes to an image. Adjusting the angle and slope of the curve will make color changes to the image's color channels.
Color Difference Equations
Mathematical equations that calculate the magnitude of difference between two colors.
Color Difference, Numerical
The difference between color coordinate values for two different samples. Quantifies the difference between two colors.
Color Difference, Visual
Visual color difference is the difference between two colors that the human eye sees. It is usually described in qualitative terms such as lighter, darker, redder, greener, bluer, yellower, paler, etc.
Color Electronic Prepress Systems (CEPS)
A digital system used to prepare color images for mechanical printing that usually involves separating the color image to CMYK values.
Color Gamut
The range of colors that a system can reproduce.
Color Look-Up Table (CLUT)
A table of color values that is used to convert from one color space to another for inputting or outputting data to different types of devices.
Color Management
The process that helps overcome variations in color reproduction workflows by creating data files that describe the unique characteristics of individual digital devices. The result enables color matching between devices, including from monitor to print, between and original photograph and a digital file, and even between two prints created on different media with different inks. The four stages (also known as the 4 C’s) of color management are consistency, calibration, characterization and conversion.
Color Management System (CMS)
A combination of software and/or hardware devices used to produce accurate color results throughout a digital-imaging system.
Color Matching Function
Relative amounts of the three additive primaries (Red, Green, and Blue) required to match wavelengths of light.
Color Measurement
Physical measurement of light radiated, transmitted or reflected by a specimen under specified condition and mathematically transformed into standardized colorimetric terms. These terms can be correlated with visual evaluations of colors relative to one another.
Color Measurement Scale
A system of specifying numerically the perceived attributes of color.
Color Model
A method of specifying a color (position) in color space, often using a coordinate system. Examples include RGB and the Munsell Color System.
Color Management Policy
Determines how the application handles color data when you open a document or import an image. You can choose different policies for RGB and CMYK images, and you can specify when you want warning messages to appear.
Color Order Systems
Method for communicating color based on three-dimensional color space. For a collection of colors to be a color order system, the collection must represent all colors in three-dimensional color space, colors must have a logical visual progression or relationship to one another, any color introduced into the system must fit into the system in a logical sequence, a slight variation to an existing color can easily be described by partial steps, the system should provide values that allow easy communication even when a sample is not provides, and the medium used to represent the system must be consistent and reproducible. One of the most well-known color order systems is Munsell.
Color Profile
A mathematical equation used to transform from one color space to another color space in order to more accurately match the output of devices. In digital printing, generally used to refer to a color profile, especially of a specific piece of equipment (monitor, printer, scanner, etc.) that enables the user to correlate color consistently on various devices. See also Color Management.
Color Proof
A color print output that is designed to provide designers and print buyers with an approximation of the color characteristics that will appear on a press.
Color Quality
The quality or “color” of light is specified as an aimpoint and tolerance in CIE color space and as a correlated color temperature. This is the correlation between the color emitted by a theoretical black body heated to a specified temperature, measured in Kelvin (K).
Color Rendering Index
Measure of the amount of color change that objects exhibit when illuminated by a light source as compared with the color of those same objects when illuminated by a reference source of comparable color temperature.
Color Reproduction
The process to reproduce colors on different devices. Two common methods used for reproducing color are additive color mixtures and subtractive color mixtures.
Color Separation
The production of a separate printing plate for each ink color that will be used to print an image. Four plates are used in process color separation, one each for Cyan, Magenta, Yellow, and Black, and an additional plate is used for each spot color.
Color Space
A three-dimensional mathematical model that includes all possible colors. The parts of the visible spectrum that can be reproduced, such as RGB for computer monitors, CMYK for print and web safe index colors for the web.
Color Space Conversion
The process of translating color from one device's color space to another, which may require approximations in order to preserve the image's most important color qualities. The translation stage attempts to create a best match between devices. If the original device has a larger color gamut than the final device, some of those colors will be outside the final device's color space. These "out-of-gamut colors" occur with nearly every conversion and are called a gamut mismatch. Perceptual, relative and absolute colorimetric are the most common rendering intents.
Color Specification
Tristimulus values, chromaticity coordinates and luminance value, or other color-scale values, used to designate a color numerically in a specified color system.
Color Specification Systems
Method for communicating colors between customers, designers and printers. The most common color specification systems are Pantone and HKS, which are often used as color guides, swatch books or color libraries.
Color Table
The color palette of up to 256 colors of an image in Indexed Color mode.
Color Temperature
A scale used to refer to the visible energy system of various light sources in degrees Kelvin as a measure of the mixture on a scale from red to blue-white. For instance, noon daylight is 5500 Kelvin, a blue-white color, while a tungsten light bulb produces an orange color at approximately 3200 Kelvin.
Color Tolerance
An acceptable color difference between a standard (reference) and a sample.
Colorant
Any substance that imparts color to another material or mixture. Colorants can be dyes or pigments.
Colorant Mixture
A mixture of dyes or pigments.
Colorimeter
A device that measures color through red, green, and blue filters and calculates values in three-dimensional color spaces that closely represent human vision. Unlike a densitometer, the filters are more closely matched to the human visual response, and circuitry within the instrument calculates values in three-dimensional color spaces that are used to represent human vision.
Colorimetry
A way of measuring and quantifying the color of an object based on a standard light source and a standard model of human vision. Three basic types of color measurement instruments are used in the graphic arts. Listed in increasing sophistication, they are densitometers, colorimeters, and spectrophotometers.
Colorist
A person skilled in the art of color matching (colorant formulation) and knowledgeable concerning the behavior of colorants in a particular material; a tinter (q.v.) (in the American usage) or a shader. The word colorist is of European origin.
Color-Matching Function
The amounts of three primary stimuli required to match equal radiant power at each wavelength.
Color Quality
The quality or “color” of light is specified as an aim point and tolerance in CIE color space and as a correlated color temperature. This is the correlation between the color emitted by a theoretical black body heated to a specified temperature, measured in Kelvin (K).
Color Temperature
A measurement in degrees that indicates the hue of a specific type of light source. Color temperature is conventionally stated in units of absolute temperature, Kelvin (K).
Color Wheel
The visible spectrums continuum of colors arranged in a circle, where complementary colors such as red and green are located directly across from each other.
Colorist
A person skilled in the art of color matching (colorant formulation) and knowledgeable concerning the behavior of colorants in a particular material; a tinter (q.v.) (in the American usage) or a shader. The word colorist is of European origin.
Complimentary Colors
Two colors that, when combined, create neutral gray. On a color wheel, complements are directly opposite the axis from each other, such as blue - Yellow, red - green, etc.
Composite Printer
A printer used to make a composite color image of a file for proofing or for final output.
Compression
The process of removing irrelevant information and reducing unneeded space from a file in order to make the file smaller. Compression can cause losses and distortion, depending on the method. The two types of compression schemes are lossy and lossless.
Computer to Plate (CTP)
In prepress, using a computer to make the plate for faster and higher quality results.
Conditional Match
A set of samples that appear to match under a limited set of conditions such as light source or viewing angle.
Consistency
The first step in the color management process, consistency is ensuring the device in a color workflow, such as a monitor, scanner or printer, is able to reproduce color consistently. See also Color Management.
Continuous Tone
An image, such as a photograph, in which there are gradual transitions between shades or colors. For printing purposes, continuous-tone images are converted to dot patterns (halftones).
Contract Proof
The basis of a contract between a printer and a client; the appearance of the contract proof should represent the appearance of final printed piece.
Contrast
Tonal gradation between the highlights, midtones, and shadows in an image. High contrast implies dark black and bright white. Medium contrast implies a good spread from black to white, and low contrast implies a narrow spread of values from black to white.
Conversion
The fourth step in the color management process, conversion is the process of matching color as closely as possible between input and output devices. For example, if an image is captured by an RGB scanner, edited in a design application, then printed on an CMYK printer, it must be converted many times. This occurs in a device-independent color space known as CIELAB, or profile connection space.
Correlated Color Temperature
The temperature in degrees Kelvin of a point on a black body locus that most closely resembles the light source.
Color Space
A three-dimensional mathematical model that includes all possible colors. The parts of the visible spectrum that can be reproduced, such as RGB for computer monitors, CMYK for print and web safe index colors for the web.
Color Space Conversion
The process of translating color from one device's color space to another, which may require approximations in order to preserve the image's most important color qualities. The translation stage attempts to create a best match between devices. If the original device has a larger color gamut than the final device, some of those colors will be outside the final device's color space. These "out-of-gamut colors" occur with nearly every conversion and are called a gamut mismatch. Perceptual, relative and absolute colorimetric are the most common rendering intents.
Color Specification
Tristimulus values, chromaticity coordinates and luminance value, or other color-scale values, used to designate a color numerically in a specified color system.
Color Specification Systems
Method for communicating colors between customers, designers and printers. The most common color specification systems are Pantone and HKS, which are often used as color guides, swatch books or color libraries.
Color Table
The color palette of up to 256 colors of an image in Indexed Color mode.
Color Temperature
A scale used to refer to the visible energy system of various light sources in degrees Kelvin as a measure of the mixture on a scale from red to blue-white. For instance, noon daylight is 5500 Kelvin, a blue-white color, while a tungsten light bulb produces an orange color at approximately 3200 Kelvin.
Color Tolerance
An acceptable color difference between a standard (reference) and a sample.
Colorant
Any substance that imparts color to another material or mixture. Colorants can be dyes or pigments.
Colorant Mixture
A mixture of dyes or pigments.
Colorimeter
A device that measures color through red, green, and blue filters and calculates values in three-dimensional color spaces that closely represent human vision. Unlike a densitometer, the filters are more closely matched to the human visual response, and circuitry within the instrument calculates values in three-dimensional color spaces that are used to represent human vision.
Colorimetry
A way of measuring and quantifying the color of an object based on a standard light source and a standard model of human vision. Three basic types of color measurement instruments are used in the graphic arts. Listed in increasing sophistication, they are densitometers, colorimeters, and spectrophotometers.
Colorist
A person skilled in the art of color matching (colorant formulation) and knowledgeable concerning the behavior of colorants in a particular material; a tinter (q.v.) (in the American usage) or a shader. The word colorist is of European origin.
Color-Matching Function
The amounts of three primary stimuli required to match equal radiant power at each wavelength.
Color Quality
The quality or “color” of light is specified as an aim point and tolerance in CIE color space and as a correlated color temperature. This is the correlation between the color emitted by a theoretical black body heated to a specified temperature, measured in Kelvin (K).
Color Temperature
A measurement in degrees that indicates the hue of a specific type of light source. Color temperature is conventionally stated in units of absolute temperature, Kelvin (K).
Color Wheel
The visible spectrums continuum of colors arranged in a circle, where complementary colors such as red and green are located directly across from each other.
Colorist
A person skilled in the art of color matching (colorant formulation) and knowledgeable concerning the behavior of colorants in a particular material; a tinter (q.v.) (in the American usage) or a shader. The word colorist is of European origin.
Complimentary Colors
Two colors that, when combined, create neutral gray. On a color wheel, complements are directly opposite the axis from each other, such as blue - Yellow, red - green, etc.
Composite Printer
A printer used to make a composite color image of a file for proofing or for final output.
Compression
The process of removing irrelevant information and reducing unneeded space from a file in order to make the file smaller. Compression can cause losses and distortion, depending on the method. The two types of compression schemes are lossy and lossless.
Computer to Plate (CTP)
In prepress, using a computer to make the plate for faster and higher quality results.
Conditional Match
A set of samples that appear to match under a limited set of conditions such as light source or viewing angle.
Consistency
The first step in the color management process, consistency is ensuring the device in a color workflow, such as a monitor, scanner or printer, is able to reproduce color consistently. See also Color Management.
Continuous Tone
An image, such as a photograph, in which there are gradual transitions between shades or colors. For printing purposes, continuous-tone images are converted to dot patterns (halftones).
Contract Proof
The basis of a contract between a printer and a client; the appearance of the contract proof should represent the appearance of final printed piece.
Contrast
Tonal gradation between the highlights, midtones, and shadows in an image. High contrast implies dark black and bright white. Medium contrast implies a good spread from black to white, and low contrast implies a narrow spread of values from black to white.
Conversion
The fourth step in the color management process, conversion is the process of matching color as closely as possible between input and output devices. For example, if an image is captured by an RGB scanner, edited in a design application, then printed on an CMYK printer, it must be converted many times. This occurs in a device-independent color space known as CIELAB, or profile connection space.
Correlated Color Temperature
The temperature in degrees Kelvin of a point on a black body locus that most closely resembles the light source.
Creep Blanket
An imperfection in printing that involves a slight displacement of the blanket forward when brought into contact with the plate or paper.
Crop
In graphic applications, the digital or manual process of cutting away unwanted portions of an image.
Crop Marks
In graphic applications, short, fine lines used for final trimming, showing the trim size of the final printed piece.
CRT (Cathode Ray Tube)
The display tube used in most televisions and standard computer monitors. An electron beam moves across the back of the screen exciting phosphor dots inside the glass tube, which causes an image to be displayed.
Curves
Graphic tools in image manipulation software that allow the user to change the contrast and color values of an image.
Custom Profile
A profile (data that characterizes a color input device, output device, or color space) that is customized for a specific device, such as a digital camera, monitor or printer.
Cylinder Covering (Dressing)
Flexible elements consisting of acetate film or paper sized assembly that are inserted under the plate and blanket to adjust the pressure between the rolls and achieve sharpness during printing.
D
D65
The CIE Standard Illuminant that represents a color temperature of 6504 Kelvin. D65 is widely used as the standard white point for monitor calibration.
Dampening Roller
On offset presses, rolls performing the wetting of the non-image areas of the plate.
Dampening Solution
In offset printing, a liquid composed mainly of water that keeps the non-image areas of a plate moistened so that they will not accept ink.
Daylight Illuminants (CIE)
Series of illuminant spectral power distribution curves based on measurements of natural daylight and recommended by the CIE in 1965. Values are defined for the wavelength region 300 to 830nm. They are described in terms of the correlated color temperature. The most important is D65 because of the closeness of its correlated color temperature to that of illuminant C, 6774K. D75 bluer than D65 and D55 yellower than D65 are also used.
Decompression
The process by which the data of a compressed file is restored.
Delta (D)
A symbol used to indicate deviation or difference.
Delta Absorbance
The difference in absorbance values, at each wavelength, between trials and the standard. Positive delta absorbance means the trial absorbs more light than the standard. Negative delta absorbance means the trial absorbs less light than the standard.
Delta E*
∆E or DE. The generic name for total color difference, and is used to indicate total color difference for all uniform color spaces. Total color difference (Delta E) is a single number that expresses the magnitude (size, degree, amount) of difference between two colors. The value tells nothing about the nature of the color difference.
Delta Ecmc
Developed by the Color Measurement Committee of the Society of Dyes and Colourists in Great Britain. DEcmc is an ellipse-based equation for computing DE values as an alternative to the rectangular coordinates of the CIE L*a*b* color space. DEcmc more closely matches human vision when judging the acceptability of color difference.
Delta K/S
The difference in K/S values, at each wavelength, between trials and the standard. Positive delta K/S means the trial has a higher absorption-to-scattering ratio than the standard. Negative delta K/S means the trial has a lower absorption-to-scattering ratio than the standard.
Delta Reflectance
The difference in reflectance values, at each wavelength, between trials and the standard. Positive delta reflectance means the trial reflects more light than the standard. Negative delta reflectance means the trial reflects less light than the standard.
Delta Transmittance
The difference in transmittance values, at each wavelength, between trials and the standard. Positive delta transmittance means the trial transmits more light than the standard. Negative delta transmittance means the trial transmits less light than the standard.
Delta Value
A conversational term for “delta color coordinate”; sometimes, the word “deltas” is used. For example, in CIELab calculations, Delta L*, Delta a* and Delta b* are all called “CIELab delta values” or “CIELab deltas.” This term is used to facilitate spoken communication.
Densitometer
An instrument used to measure color through red, green and blue filters, similar to those used for color separation. The filters make their complimentary color inks look dark, thus it has been said that densitometers “see” in black and white.
Density (Optical Density)
The degree of opacity of an image. The higher the density, the darker the image. Density measurements of solid ink patches are used to control ink on paper.
Descreening
Applying controlled blur when scanning halftone images to make them appear more like a continuous tone image and to minimize moiré patterns.
Desktop Color Separation
A file format consisting of four .eps files, one for each of the process colors Cyan, Magenta, Yellow, and Black.
Device Dependent Color
A color space (LAB) that is unique to a specific device and its color rendering capabilities.
Device Profile
Mathematical equations or look-up tables used to transform from a common color space to the specific color space of a device.
Device-Independent Color
Color specifications that are based on an independent color model (RGB, CMYK) rather than the gamut of an output device.
Device-Independent Color Space
A color space that can be used to describe all the colors seen by the human eye, independent of the colorants used to reproduce colors for a specific device.
Device Specific Color Space
A color space that is defined based on how a specific device reproduces color. RGB and CMYK are both device specific color spaces.
Diffuse Dithering
A method for printing continuous tone images on a laser printer in which the grayscale information is represented by randomly located printer dots.
Diffuse Reflection
Reflection in which light energy is scattered in many directions by diffusion at or below the surface.
Diffuse Transmission
Diffusion of light energy being transmitted through a sample and subject to the laws of refraction.
Diffused Light
Nondirectional or scattered light.
Digital Camera
Any camera system that is capable of capturing image data into a digital file.
Digital Camera Profile
A digital camera profile describes the conversion of the digital camera specific RGB space to the CIELab system. The test chart determines which colors form the original will be converted to which RGB colors of the digital camera. However, since a test chart only covers part of the digital camera's entire gamut, it is the profiling software's job to supply a description of those colors that are in the outer areas of the device gamut.
Digital Color Printing
A non-impact printing technology in which digital data is output to inkjet, electrostatic thermal transfer, dye sublimation, and photographic printing devices on a pixel-by-pixel basis.
Digital Halftone
The reproduction of color and spatial resolution for digital image data using a series of dots arranged in a square pattern.
Digital Imaging
The process of image capture, manipulation and final image form, accomplished by digital systems.
Digital Photographic Printing
Any of a number of printing devices that expose photographic paper to LED, laser, or CRT light sources using a digital data input and pixel-by-pixel exposure.
Digital Printer
Any device that is capable of translating digital data into hardcopy output. Typically refers to one of the digital output technologies, such as inkjet, electrostatic, thermal transfer, or laser photoprinting.
Direct-to-Press Printing
The printing process that allows for the elimination of film separations from the printing process.
Display Profile
They describe the color spaces of the camera and the image. The monitor's profile tells the color management system how to translate the image's colors to the monitor's color space.
Dithering
The process used by some output devices to simulate shades of gray or color variations with a randomizing technique that uses varying sizes of and shapes of pixel groupings instead of an ordered array of halftone dots.
Dmax
A measure of maximum density; the blackest black possible.
Dmin
The lowest level of density.
Dot Gain
The phenomenon that occurs when ink expands its coverage during printing onto a substrate; often caused by abnormal or excessive absorption by the substrate. Also, the spreading of dots during platemaking or on a printing press as wet ink is pushed into the paper and possibly absorbed by it, which causes colors or shades to look darker.
Dot Pitch
The distance between the dots on a computer monitor, typically 0.24 to 0.38 mm. The closer the dots, the sharper the image on the monitor.
Down-Sampling
The reduction in resolution of an image that results in a loss of detail.
Dots per Inch (dpi)
A measure of printer resolution that indicates how many ink dots the printer can place in one inch, either vertically or horizontally.
Driver
A program that allows a hardware peripheral device to communicate with a computer.
Drum Scanner
A type of optical scanner where a flexible original is mounted to a rotating drum. As the drum spins, light is captured from the image point by point, using a photomultiplier tube detector.
Dry Down
The amount of time it takes for inks to become stable.
Duotone
A two-color reproduction of a single-color image or a grayscale image that is printed using two plates to enhance its tonal depth.
Dye
A colorant that does not scatter light, but instead absorbs and reflects certain wavelengths and transmits others. Dyes are generally organic and usually soluble in water or some other solvent system.
Dye Sublimation (Diffusion Transfer)
A color printing technology that forms an image by delivering gaseous dyes to the receiver material with a thermal driver.
Dynamic Range
The extent of values from lightest to darkest.
E
Early-Binding Workflow
Converting all colors into the final output space as soon as possible.
Effective Resolution
The final appearance of a scan that has been enhanced to produce more data than the scanner can record. This is done by interpolation.
Eight-bit (8-bit) Color
Each pixel has eight bits assigned to it, providing 256 colors or shades of gray. A grayscale image is an example of 8-bit color.
Electromagnetic Spectrum
The range of all possible frequencies of electromagnetic radiation. Light is a particular type of electromagnetic radiation that can be seen and sensed by the human eye, but this energy exists at a wide range of wavelengths. The micron is the basic unit for measuring the wavelength of electomagnetic waves. The spectrum of waves is divided into sections based on wavelength. The shortest waves are gamma rays, which have wavelengths of 10e-6 microns or less. The longest waves are radio waves, which have wavelengths of many kilometers. The range of visible consists of the narrow portion of the spectrum, from 0.4 microns (blue) to 0.7 microns (red).
Electrostatic
A process of imaging where a "toner" is used to form an image by controlled static charges. Toner printing adheres to the charged areas.
Ellipsoid
A solid whose plane sections are all ellipses (closed curves produced when a cone is cut obliquely to its axis by a plane).
Embedded Profile
Define the character of color in an image. Embedded profiles can be RGB, CIELab, CMYK or grayscale, and depend on the selected color working space or the originating device.
Emissive Object
An object that emits light. Emission is usually caused by a chemical reaction, such as the burning gasses of the sun or the heated filament of a light bulb.
Emulsifying Agent
A substance used to mix inks that facilitates the dispersion of one liquid into another.
Encapsulated PostScript (EPS)
A metafile file format developed by Adobe that supports both bitmap and vector based images and graphics. This file format is supported by various applications and is commonly used to transfer files between applications. The file format supports RGB, CYMK, and LAB color spaces and is a commonly used format for moving files from one application to another and for color separation.
Encryption
The act of encoding a file through use of software programs so that others may not gain access to its content.
Encapsulated PostScript (EPS)
A metafile file format developed by Adobe® that supports both bitmap and vector based images and graphics. This file format is supported by various applications and is commonly used to transfer files between applications. The file format supports RGB, CYMK, and LAB color spaces and is a commonly used format for moving files from one application to another and for color separation.
Error Diffusion
A printing technology that uses random dot placement to achieve optimal results.
EVGA (Extended Video Graphics Array)
A video display with 1024 x 768 pixel resolution.
Expanded-Gamut Printing
A printing system where manufacturers add additional colors of ink to expand the range of the standard CMYK inkset. Lighter densities of Cyan and Magenta (LC, LM), Orange and Green (O, G) and multiple Blacks are the most popular.
Exposure
The amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film or electronic image sensor.
Extended Gamut Printing
A printing system where manufacturers add additional colors of ink to expand the range of the standard CMYK inkset. Lighter densities of Cyan and Magenta (LC, LM), Orange and Green (O, G) and multiple Blacks are the most popular.
Extended Graphics Array (XGA)
DesAn IBM standard display mode providing 1,024 x 768 pixels of spatial resolution and 256 colors.criptor
F
False Colors
Refers to a group of color rendering methods used to display images in color that were recorded in the visible or non-visible parts of the electromagnetic spectrum.
Feather
A technique available in many image-editing programs that softens the edges around a selection or fades an area over a specified number of pixels.
File Compression
Reducing the size of a file, which is important when transmitting files. The two basic types of compression are lossy and lossless.
File Format
A particular arrangement of digital information that is saved from an application program for a specific use, such as Graphics Interchange Format (GIF) and Tagged Image File Format (TIFF).
Filters
In an image-editing application, a function that uses algorithms to modify digital images by changing the values or arrangement of specific image areas. Also, an optical device that selectively attenuates the intensity of light passing through it according to the light's properties. Common filters attenuate light according to either wavelength or polarization state.
Firewall
A security system that prevents unauthorized access to resources or information on a network from being passed on to another network.
Flare
Non-imaging stray light that can cause image degradation.
Flash
An Adobe® application used for the delivery of vector graphics and sound over the Internet.
Flatbed Scanner
A type of scanner that captures image data using a linear array detector.
Flexographic Printing
A process of rotary letterpress printing using flexible plates and fast-drying inks.
Fluorescence
Process by which energy, usually UV, is absorbed by certain chemicals or materials and re-emitted at other, usually longer, wavelengths.
Fluorescent Lamp
A low pressure mercury electric-discharge lamp in which a fluorescing coating (phosphor) transforms some ultraviolet energy generated by the discharge into visible light.
Fluorescent Whitening Agent (FWA)
A fluorescent dye or pigment that absorbs UV energy and re-emits the energy at a higher wavelength as visible light (violet blue) thereby causing a white appearance.
FMC-2
A color difference equation developed by Friele, MacAdam and Chickering. The equation was derived from the results of an extensive visual assessment experiment. For most colors, a total color difference (Delta E) value of 1.0 represents a just- noticeable difference.
FOGRA
The FOGRA Graphic Technology Research Association, located in Munich, Germany, is focused on research and development for printing technology. FOGRA's tasks are research, development, transfer of know-how to industry, development of standards, consultancy and technical reports.
Foot Candle
The quantity of light at a point on a plane surface one foot from and perpendicular to a standard candle.
Font
Any given typeface containing all of the numbers, letters and symbols.
Format
A printer’s print area, or a media/graphic’s width. "Medium format" is generally 11-24" in width, "large (wide) format" is generally larger than 24” in width; and "grand format" is usually larger than 72" in width.
Four-Color Process
The printing process that uses Cyan, Magenta, Yellow, and black inks to simulate a wide variety of colors, also called CMYK or process printing.
FPO (For Position Only)
A term for a low-resolution image used in page layouts to define the proper placement of the hi-resolution image.
Fractal
A mathematically-generated pattern with an infinite amount of image detail.
Fractal Compression
Compression scheme based upon converting image files into mathematical equations. The method can produce very high compression ratios.
Frequency Modulation (FM) Screening
A halftone screening method in which all halftone microdots are the same very small size, but their average number per surface area, or frequency, varies according to the tone value to be reproduced.
Full Bleed
A printing term used when an image or inked area extends beyond the edge of all four sides of the printed piece.
G
Gamma
A measure of the amount of contrast found in an image according to the slope of a gradation curve. High contrast (steep curve) has high gamma, and low contrast (shallow curve) has low gamma.
Gamma Correction
The non-linear tonal correction editing of an image’s gamma curve. This is typically used to manipulate image shadow detail and lighten the image without washing out the highlight areas.
Gamut
The range of colors available in an image or output process. A color is said to be "out of gamut" when its position in one device's color space cannot be directly translated into another device's color space.
Gamut Compression
Editing an image to reduce the color gamut so the image can be displayed or output within the limits of a particular device.
Gamut Mapping
Plotting an image color gamut into the CIE color space.
Gas Ghosting
The phenomenon where uncured inkjet prints, when framed, form a fogged or ghost image on the inside of the glass surface. This happens primarily with "barrier-type" paper, such as RC papers, and can be avoided with thorough or accelerated drying of the print.
Gaussian Blur
An image softening effect using a bell-shaped gaussian distribution to soften the image.
Generation Loss
The loss of image quality or data as the image is reproduced multiple times.
Geometric Attributes
The characteristics associated with light distribution from an object including gloss, haze, texture, shape, viewing angle and surround.
Geometric Metamerism
The property exhibited by a pair of samples (usually highly textured) that appear to match at one illumination and viewing angle, but no longer match when either the angle of illumination or viewing angle is changed.
Ghosting
In image editing software, the effect of changing an object’s level of opacity.
Graphics Interchange Format (GIF)
A data compression format most commonly used for displaying images on the Internet.
Global Color Correction
Color correction in a digital image that affects the entire image.
Gloss
An additional parameter to consider when determining a color standard, along with hue, value, chroma, the texture of a material and whether the material has metallic or pearlescent qualities. Gloss is an additional tolerance that may be specified in the Munsell Color Tolerance Set. The general rule for evaluating the gloss of a color sample is the higher the gloss unit, the darker the color sample will appear. Conversely, the lower the gloss unit, the lighter a sample will appear.
Gloss Differential
A problem that can occur with certain ink/paper combinations where darkened, or "bronzed," reflections from inked areas are juxtaposed with areas where little or no ink is present, resulting in full reflection of the paper. Also called "bronzing."
Glossmeter
An instrument used to measure the amount of gloss (a term used to describe the relative amount of mirror-like (specular) reflection from the surface of a sample). These instruments measure the light reflected at selected specular angles, such as 20 degrees from the perpendicular, 45, 60, 75, and 85 degrees. Results obtained are very dependent on instrument design, calibration technique used, types of samples, and so forth.
Goniochromatic
Adjective used to describe a colored material that exhibits goniochromatism.
Goniochromatism
The phenomenon where the color of a material changes as the angle of illumination or viewing is changed.
Goniospectrophotometer
An instrument used to measure a spectrophotometric curve at various angles of incidence and reflectance. The angles of incidence and reflectance can be changed or are offered at fixed intervals (e.g., 15, 45, 75, 110 degrees).
Gradation
A smooth transition between two colors.
Graphics File Format
A file format used to store any of the file formats for storing images in a digital form, such as GIF, BMP, JPG, and TIF.
Graphic Interchange Format (GIF)
An image format type generated specifically for computer use. Its resolution is usually very low (72 dpi, or that of your computer screen), making it undesirable for printing purposes. GIF is supported by various applications and uses LZW lossless compression.
Graphics Tablet
A device that provides intricate control of cursor movements by using a stylus or pen for drawing or graphics programs.
Gravure
An intaglio printing process that uses engraved cylinders that retain ink in engraved areas; ideal in long-run work, such as magazines and packaging, and prints on most substrates.
Gray Component Replacement (GCR)
The process of removing areas of overlapping Cyan, Magenta, and Yellow inks and replacing that amount with Black ink in the black separation.
Grayscale
An achromatic scale ranging from black through a series of successively lighter grays to white. Such a series may be made up of steps that appear to be equally distant from one another (such as the Munsell Value Scale), or it may be arranged according to some other criteria such as a geometric progression based on lightness. Such scales may be used to describe the relative amount of difference between two similar colors.
Gumming
In offset lithography, an operation which is intended to spread a thin gum dried film on the surface of non-image areas to avoid oxidation by oxygen in the air.
H
h
Hue angle coordinate in CIE L*C*h color space. The angle refers to the hue's location in the CIE L*C*h color wheel, where red is 0, yellow is 90, green is 180, and blue is 270.
Halftone
A process for representing the tones in an image by dots of varying sizes.
Halftone Cell
A matrix of printer dots that can be combined to produce varying sizes of halftone dots.
Hard Proof
The printed proof of a document to show how colors will look when reproduced on a specific output device, usually a commercial printing press.
Haze
The scattering of light by a specimen responsible for the apparent reduction of contrast of objects viewed through it or contrast of objects viewed by reflection at the surface.
Heatset Ink
Used in an offset printing press, a specially formulated greasy ink in which the binder or vehicle includes solvents. Drying is accelerated by increased temperature.
High-Fidelity Color
The extension of the tonal range of color images by means of stochastic printing and the use of six or more color inks to print images rather than the traditional four colors used in the CMYK process.
Highlight
The area of a glossy object over which specular reflection can be viewed. It is normally the color of the light source, not of the object.
Histogram
A graphical representation of the tonal values (brightness or color) in a scene based upon the frequency of occurrence of each value.
HSB (Hue, Saturation, Brightness)
A three-coordinate, device-independent color model in which numerical values describe hue, saturation, and brightness.
HSL (Hue-Saturation-Lightness)
A color space used to represent images based on polar coordinates. Intensity is the vertical axis of the polar system, hue is the relative angle, and saturation is the planar distance from the axis. HSL is thought to be more intuitive to manipulate than RGB space.
HSV (Hue-Saturation-Value)
A color space that describes color using three basis components: hue, saturation and brightness.
HTML (Hyper Text Markup Language)
A computer language using a standard group of tags to tell a web browser how to display text and graphics.
HTTP (Hyper Text Transfer Protocol)
The standards that let users of the web transfer information in web pages.
Hub
A device that connects two or more devices so they can communicate.
Hue
The attribute of color used in the Munsell Color System by which we distinguish red from green, blue from yellow, and so forth.
Hunter Lab
A uniform (opponent color scale) color space in which colors are located within a three-dimensional rectangular coordinate system; the three dimensions are lightness (L), redness/greenness (a), and yellowness/blueness (b).
I
ICC (International Color Consortium)
A group of companies in agreement that develop standards defining color and reproduction characteristics of hardware/software devices and media independent of device-specific characteristics.
ICC Profiles
A set of data that characterizes a color input device, output device, or color space, according to ICC standards. Profiles describe the color attributes by defining a mapping between the device source or target color space and a profile connection space, either CIELAB (L*a*b*) or CIEXYZ. Every device that captures or displays color can have its own profile. The ICC standard provides for profiles in RGB format for scanners, digital cameras, and monitors; in CMYK format for printers and proofers; and in multi-color format for multi-color printing processes.
Illuminance
The amount of light falling into a patch of unit surface area, measured in lux.
Illuminant
An illuminant is a mathematical representation of a theoretical real light source, used for calculating tristimulus values from a spectrophotometric measurement. The numbers represent relative power of the theoretical source at each point in the visible spectrum. The relative power distribution of a real source could be used for calculation, but real sources are difficult to standardize.
Illuminant A
Mathematical representation of tungsten halogen (incandescent). Color temperature: 2856K. Uses include metamerism testing. Simulates typical home or store accent lighting.
Illuminant C
Mathematical representation of filtered tungsten halogen (daylight). Color Temperature: 6770K. Uses include metamerism testing. Simulates the CIE average daylight.
Illuminant CWF-2 (F2)
Mathematical representation of commercial, wide band fluorescent used in the USA (Cool White Fluorescent). Color temperature: 4150K. Uses include metamerism testing. Simulates typical office or store lighting in the USA.
Illuminant D50
Mathematical representation of noon sky daylight. Color temperature: 5000K. Uses include general evaluation of color, metamerism testing, and evaluating color uniformity and quality in the graphic arts industry.
Illuminant D55
Mathematical representation of noon sky daylight. Color temperature: 5500K. Uses include metamerism testing. Simulates the CIE average noon sky daylight.
Illuminant D65
Mathematical representation of average north sky daylight. Color temperature: 6500K. Uses include general evaluation of color, metamerism testing, providing visual correlation with spectrophotometric instrumental readings, and conformance with European and Japanese standards. Simulates average north sky daylight.
Illuminant D75
Mathematical representation of north sky daylight. Color temperature: 7500K. Uses include general evaluation of color, metamerism testing, and visual evaluation of opaque materials as outlined by ASTM D1729. Simulates north sky daylight.
Illuminant DLF-7
Mathematical representation of commercial, wide band fluorescent used in the USA (Deluxe). Color temperature: 6500K. Uses include metamerism testing.
Illuminant NBF-11
Mathematical representation of commercial, narrow band fluorescent used in the USA. Color temperature: 4000K. Uses include metamerism testing. USA equivalent to TL84.
Illuminant SPL (D65)
Mathematical representation of GretagMacbeth-patented Filtered Tungsten Halogen as found in SpectraLight (Daylight). Color temperature: 6500K. Uses include critical evaluation of color, metamerism testing, providing visual correlation with spectrophotometric instrumental readings, conformance with European and Japanese standards, and agreement with the current Automotive standard. Simulates average north sky daylight.
Illuminant SPL (D75)
Mathematical representation of GretagMacbeth-patented, Filtered Tungsten Halogen as found in SpectraLight (Daylight). Color temperature: 7500K. Uses include critical evaluation of color, metamerism testing, and visual evaluation of opaque materials as outlined by ASTM D1729. Simulates north sky daylight.
Illuminant SPL (HOR)
Mathematical representation of Tungsten Halogen as found in SpectraLight (Horizon). Color temperature: 2300K. Uses include metamerism testing. Simulates early morning sunrise or late afternoon sunset.
Illuminant TL83
Mathematical representation of commercial, rare earth phosphor, narrow band fluorescent used in Europe and the Pacific Rim. Color temperature: 3000K. Uses include metamerism testing. Simulates typical office or store lighting in Europe and the Pacific Rim.
Illuminant TL84
Mathematical representation of commercial, rare earth phosphor, narrow band fluorescent used in Europe and the Pacific Rim. Color temperature: 4100K. Uses include metamerism testing. Simulates typical office or store lighting in Europe and the Pacific Rim.
Illuminant TL85
Mathematical representation of commercial, rare earth phosphor, narrow band fluorescent used in Europe and the Pacific Rim. Color temperature: 5000K. Uses include metamerism testing. Simulates typical office or store lighting in Europe and the Pacific Rim.
Illuminant U30
Mathematical representation of commercial, rare earth phosphor, narrow band fluorescent. Color temperature: 3000K. Uses include metamerism testing. Simulates typical store lighting for Sears. USA equivalent of TL83.
Image Enhancement
Processing an image to improve elements such as color, tonal range, and defects.
Imagesetter
A high-resolution printer (usually between 1,270 and 4,000 dpi) used in the printing industry to image a bitmap to a light-sensitive substrate.
Import
The ability of a software application to bring in files that are not in the same native file format.
Imposition
The process of positioning pages of a publication into the correct position to ensure proper page order after printing and binding.
Incandescent
A lamp in which light is produced by a filament heated by an electric current so that it glows.
Index Color
A subset of colors of a specific color system that define the palette used in an image.
Ink
A fluid or viscous substance used for writing or printing. In digital printing, the substance in inkjet printing (liquid or solid) that gets sprayed onto the medium, which consists of a colorant, a solvent or vehicle, and various additives.
Ink Additive
Resins used as additives in commercial printing inks to modify the adhesivity, film toughness and glossiness of ink.
Ink Fountain
A reservoir or tray attached to the offset press that contains printing ink.
Ink Limiting
A control within a program that limits the percentage of ink applied to an area of print.
Inkjet Printer
A type of non-impact printing technology that sprays tiny drops of ink onto a surface.
Ink Stripe
A band of ink left on the plate that indicates the pressure of the rollers.
Inking
Distribution of the ink on the form by the inking rollers.
Input Device
Any hardware device that sends information to a computer, such as a digital camera or scanner.
Input Profile
Describes the color attributes of a particular input device, such as a digital camera or scanner, to enable accurate color conversions to an output device.
Integrating Sphere
A sphere manufactured or coated with a highly reflective material that diffuses light within it.
Interlaced Display
A technique for displaying images at a higher resolution than the monitor. Two images consisting of every second row of pixels are alternately displayed during every screen refresh (e.g. every fiftieth of a second), creating a flickering artifact.
Internet
A set of interconnected networks that form a global TCP/IP network.
Internet Service Provider (ISP)
An organization that sells access to the Internet.
Interpolated Resolution
A process for increasing image size by using nearby pixels to estimate the color for pixels in the new, larger image. By averaging the color values of surrounding pixels, new image pixels can be created to help alleviate the jaggies (also known as stairstepping).
Intranet
An internal network that uses the TCP/IP standard to allow the sharing of resources, such as printers, files, and storage space on a server.
Invert
To reverse an image's light and dark values and/or colors.
IP (Internet Protocol Address)
The address of a computer on a TCP/IP network written as four groups of up to three digits separated by periods, e.g., 121.119.115.11.
ISO
A representation of the light sensitivity of an image sensor; the higher the number, the higher the sensitivity to light. Noise may increase as ISO increases.
IT8
Standard test targets for color characterization of different devices and media such as scanners and printers established by the Committee IT8 of the American National Standards Institute (ANSI).
J
Jaggies
The effect caused by images or lines being rendered at too low a resolution, which produces a stair-stepped effect that gives the image a rough appearance. Also known as “aliasing.”
JPEG (Joint Photographic Experts Group)
A bitmap, 24-bit color file format that allows the user to specify the amount of lossy compression applied to the file. This file format is supported by most imaging applications and is most appropriately used on continuous tone images.
JPEG 2000 (JPEG 2000: Image Coding System)
Officially called ISO 15444, a standardized format that will expand the ability to manage and transport continuous tone images without noticeable loss of quality.
K
K/S (“K over S”)
The ratio of the absorption coefficient (K) versus the scattering coefficient (S) for a reflectance measurement. The ratio is derived mathematically from the reflectance measurement as follows: where R is reflectance expressed as a decimal (for example, 60%R is 0.6R).
Kelvin (K)
The unit in which color temperature is measured that is used in imaging to define the quality of a light source by referring to the absolute temperature of a black body that would radiate equivalent energy. Generally, a tungsten reading lamp is rated at 2800 degrees Kelvin, TV or film quartz lights are rated at 3200 degrees Kelvin, and outdoor light averages around 5600 degrees Kelvin. The higher the Kelvin temperature, the more bluish the light appears.
Kernel Size
The number of pixels sampled in image manipulation and sharpening processes.
Key
The term for black ink in the CMYK printing process.
Kiosk
A self-serve station set up in a public location that allows customers access to various imaging capabilities and output.
Kubelka-Munk
Phenomenological turbid-medium theory relating the reflectance and transmittance of scattering and absorbing materials to optical constants. Theory includes variables where K represents the absorption coefficient and S the scattering coefficient for the concentrations of colorants. Also known as K over S data, this relationship is the basis of virtually all computer color matching calculations.
L
L*a*b* (CIELAB)
The color model that best describes human vision. The model consists of three variables: L* for luminosity, a* for one color axis, and b* for the other color axis.
Lambert’s Law
The flux reflected per unit solid is proportional to the cosine of the angle measured from the normal (perpendicular) to the surface.
LAN (Local Area Network)
A group of computers that operate over a limited distance, for example within an office or building.
Lacquer
Clear, water based resins or solvents applied to a printed sheet to protect it or provide a gloss, matte, or satin finish.
Large Format
A printer, media, or print that is 24" or greater in width.
Laser
An intensely focused beam of light with a very narrow spectral distribution. Lasers are used in writing data to storage medium such as CD, or in certain types of digital printers.
Laser Printer
A printer that uses a laser beam to write on a photoconductive revolving drum that is coated with toner. After the image is transferred to paper, it passes through a pair of heated rollers or a fuser that melts the toner to fuse it with the paper fibers.
Lasso
A tool found in many image editing applications allowing the user to select an area of an image by drawing a line around it.
Late-Binding Workflow
Delaying color conversion to the final output space until the end of the workflow.
Lux
A measure of the intensity of light that hits or passes through a surface, as perceived by the human eye.
Layer
A level of an image that can be edited independently from the rest of the image.
Layering
In image editing software, the placement of one image or graphic over another so the opacity of the top image can allow the lower image to show through.
LCD (Liquid Crystal Display)
A computer display technology based upon the changing optical density of certain types of molecules when placed in an electric field. LCD displays can be active-matrix or passive-matrix.
LED (Light Emitting Diode)
A semi-conductor that emits light when an electric charge passes through it. LEDs are used in displays as well as in certain types of digital photo printers.
Lenticular
The combination of interlaced digital images that when viewed with a specially designed, plastic lens creates the illusion of depth or motion.
Light
Electromagnetic radiation that has a wavelength in the range from 380 (Violet) to about 770 (Red) nanometers (nm), and can be perceived by the normal, unaided human eye.
Light Source
That element in an instrument or in the visual observing situation that furnishes radiant energy in the form of light. The emission also may be described in terms of its correlated color temperature.
Lightfast
Resistant to the destructive action of light.
Lightness
One of the three dimensions describing color. The attribute by which observers distinguish white objects from gray objects and light colored objects from dark colored objects.
Line Art
Single color diagrams or drawings. An image that requires sharp edges and high contrast between areas of the image that have ink, and those areas that do not. A drawing that consists only of black and white with no intermediate grayscale information. These images require a higher resolution to create the necessary sharpness.
Linear Array
An image sensor composed of Red, Green, and Blue photo sites arranged in a row.
Linearization
The process of measuring and correcting for a device's inability to see or reproduce a straight line of tones from black to white. Linearization is a critical first stage in setting up any color system.
Line Screen
A printing term that defines the density of the elements of a halftone cell as the number of lines of ink dots per inch or millimeter.
Lithograph
The process of printing from a stone or metal plate on which the image to be printed is ink-receptive and the blank area is ink repellent.
Local Color Correction
Color correcting that only affects a selected area of an image.
Log Absorbance
The base 10 logarithm of absorbance values at each wavelength. A spectral plot (log absorbance versus wavelength) shows that vertical distances between two curves (samples) are virtually the same for all wavelengths. Therefore, the vertical position of the curve relates directly to the colorant concentration or sample thickness. Also, the shape of the curve is independent of colorant concentration or sample thickness.
Log K/S
The base 10 logarithm of K/S values at each wavelength. A spectral plot (log K/S versus wavelength) shows that vertical distances between two curves (samples) are virtually the same for most wavelengths. Therefore, the vertical position of the curve relates directly to the colorant concentration. Also, the shape of the curve is almost independent of colorant concentration.
Look-Up Table (LUT)
A table of color values that is used to either convert from one color space to another for inputting or outputting digital data to different types of output devices.
Lossless Compression
A compression technique in which smaller file sizes are achieved without the loss of any of the original data values. This is achieved by a variety of encoding schemes that allow the original data to be re-created from the compressed format.
Lossy Compression
A compression technique in which smaller file sizes are achieved by eliminating some of the original image data. The amount of the original data to be maintained is arbitrarily set by the user based upon the required quality for the intended use.
lpi (Lines per Inch)
The number of lines per inch in a halftone screen. As a general rule, the higher the lpi, the higher the printed resolution and quality.
Lumen
A measure of the rate at which a source emits light. The ANSI lumen is used to define the brightness of overhead and video display projectors.
Luminance
The rate at which a source emits light in a specific direction. Also, the brightness part of a composite video signal.
Luminosity
The distribution of an image's light and dark values.
Luster
The appearance characteristic of a surface that reflects more in some directions than it does in other directions but not of such gloss as to form clear mirror images.
Lux
A measure of the intensity of light that hits or passes through a surface as perceived by the human eye.
M
MacAdam Ellipses
Ellipsoids plotted on the chromaticity diagram that correspond to a just-notice- able difference from the color represented by the center of the ellipsoid. The size and shape of the ellipsoids depend on their location on the chromaticity diagram.
MacAdam Unit
A unit of color difference as calculated by the FMC-2 equation. One (1:0) MacAdam unit corresponds to a just-noticeable difference, based on experimental results.
Marquee
A selection tool in image editing programs typically represented by animated dotted lines around the selected area.
Mask
A special effect that can modify images so that only part of the image can be seen, or so that the image blends into the background.
Match
Generally, two colors match if they appear to be the same (have the same color coordinate values). The word “match” is often used to indicate a spectral match, which means the two colors will appear to be the same (have the same color coordinates) regardless of illuminant or observer.
Matrix
The plate or surface upon which an image is inscribed in order to hold ink before transferring the image to a substrate or paper. In digital terms, the matrix becomes the electronic file located on a computer’s hard drive or stored on a disk or CD. This matrix is made up of binary encoded information that can describe to how the image file should appear on the digital raster screen or print.
Matte Finish
A surface which displays no gloss when observed at any angle; a highly diffusely reflecting surface.
Media
A material to be printed on, such as paper, canvas, cotton, or plastic. Media and substrate are the most common terms used in digital printing.
Metafile
A file format that contains both bitmap and vector data, that can be used on different machines and in different applications.
Metameric Pair
A pair of colors that match when viewed under one set of viewing conditions, but no longer match if the viewing conditions are changed.
Metamerism
A phenomenon exhibited by a pair of colors which match under one or more sets of real or calculated conditions and not match when these conditions are changed.
Metamerism Index (MI)
A special formula that calculates the difference between two colors under two different light sources. An MI of greater than 2.0 usually indicates that the metamerism is visible to the human eye.
Mezzotint
A tonal engraving process where the surface of the plate is roughened with a mesh of small burred dots, then the picture is produced by flattening and burnishing selected areas that print as highlights.
Microporous
An inkjet media that has a receptor coating with voids that fill with ink. The ink is rapidly absorbed within the media rather than being applying to the surface. This rapid absorption makes it instantly "dry" to the touch.
Midtones
Tones in an image that are in the middle of the tonal range, halfway between the lightest and the darkest. Also called "middle values."
Missing (Mismatched) Profile
In Adobe® Photoshop®, a Profile Mismatch message indicates the software has encountered an image where the embedded profile is different than the current working space.
Moiré
An undesirable pattern effect that occasionally appears in combinations of overlapping halftone screens. Changes to screen angles will often eliminate these patterns.
Monitor Calibration
The process of adjusting a video display to a known set of values in order to closely match input and output devices.
Monitor Profile
A monitor profile describes the RGB corner coordinates, the gradations curves for each color channel, the black point and the white point.
Monochrome
An image made of a range of only one color.
Monoprint
One of a series in which each print has some differences of color, design, texture, etc. applied to an underlying common image.
Montage
The seamless combination of divergent images into a singular image.
Morphing
To blend two images together by smoothing moving points from their original position to new positions to form a single image.
Mottling
A texturing seen in the smooth or monotone areas of an image that can be due to faulty processing and a number of improperly used digital processes, such as excessive unsharp masking.
MPEG (Motion Picture Expert Group) Compression
A variety of video and audio compression techniques that can reduce the data files at ratios of up to 200:1.
Multicolor Printing
Process color printing, with the addition of a fifth, sixth or seventh color to extend the color gamut and produce more accurate colors. PANTONE Hexachrome® is a six-color system, which includes Orange and Green for printing with an extended color gamut.
Multimedia
A synthesis of digital media types combining texts, graphics, audio, animation, and video in an interactive format.
Munsell System (of Color Notation)
A color model that identifies specific colors by their hue, value, and chroma. The system consists of over 3 million sample observations of what people perceive to be like differences in hue, chroma, and value.
N
Nanometer (nm)
Unit of measure equal to one millionth of a millimeter. Wavelengths are measured in nanometers.
Narrow Band Fluorescent
Generic term for fluorescent lamp products such as Ultralume and TL84 that produce narrow bands of visible light energy as a function of their phosphor blend.
Noise
Random recoloring of pixels to create a grainy pattern.
Non-Impact Printer
Any printing technology in which marks are made on paper without physical contact between the printer and the paper.
Non-Interlaced
A video system that displays all of the horizontal lines across the screen in succession. Computer monitors are usually non-interlaced while television video monitors are often interlaced.
Non-Metameric Match
A pair of colors which appear to be identical to all observers under all conditions of illumination and viewing; an unconditional match.
Normal Color Vision
Vision of a normal observer who exhibits no symptoms of anomalous or defective color response.
O
Object
In multimedia, a video clip, audio file or graphical representation stored data element; a vector-based drawing.
Observer Functions
The response of the average normal human eye at each wavelength has been measured through extensive experimentation by the CIE. Since there are three color sensor types, there are three observer functions that comprise what is known as the standard observer.
Observer
The human viewer who receives a stimulus and experiences a sensation from it. In vision, the stimulus is a visual one and the sensation is an appearance.
Observer Metamerism
A pair of colors which match when viewed by one observer, but no longer match when viewed by another observer.
Observer, Standard
The spectral response characteristics of the average observer defined by the CIE. Two such sets of data are defined, the 1931 data for the 2 visual field (distance viewing) and the 1964 data for the annular 10 visual field (approximately arm's length viewing).
OCR (Optical Character Recognition)
The technology used to convert scanned text on printed pages into editable ASCII text.
Offset Printing (Offset Lithography)
A commercial printing method where ink is offset from the printing plate to a rubber roller, then to paper.
OLE (Object Linking and Embedding)
A standard that provides a software channel for inserting an object in a document that still has a link to its original application.
On-Demand Printing
A digital application of printing in which documents can be output from a database directly to the print device in variable quantities as often as demanded.
Opacity
Lacking transparency or translucence. The measure of the amount of light that can pass through a material. The density of a layer or color.
Opaque
Term used to describe complete opacity, i.e. degree to which a specimen obscures the substrate beneath it; opposite of transparent.
Operating System
The system used by the computer to control basic input and output operations and allow the operation of software applications. Examples include Mac OS, Windows, UNIX, and Linux.
Opponent Color Theory
Theory explaining conceptually how the human visual system (eye and brain combination) perceives color. To the human visual system, red and green are opposites, and yellow and blue are opposites. To a human observer this means that something that is red has no green in it (it may also be blue or yellow), while something that is yellow has no blue in it (it may also be red or green). Something that is neither red nor green is neutral with respect to redness/greenness. Something that is neither yellow nor blue is neutral with respect to yellowness/blueness. If a color is neutral with respect to both, it is a “colorless” neutral (such as a black, gray or white). This theory is the basis for most uniform color spaces (especially CIELab, CIELCh, and Lab).
Optical Resolution
The maximum physical resolution of a device. Optical Resolution provides better image quality than interpolated resolution, which uses software to create additional image information.
Orientation
The direction that the page is printed; horizontal = landscape, vertical = portrait.
Out-of-Gamut
In commercial printing, a range of colors that cannot be reproduced within the CMYK color space.
Output Device
A hardware device that displays information from a computer, such as a monitor or printer.
Output Profile
Describes the color attributes of a particular output device, such as a monitor, projector or printer, to enable accurate color conversions from an input device.
P
Palette
The range of color or tone available in the imaging process. Also, a movable menu of tools or options found in software applications.
PANTONE®
A company best known for its Pantone Matching System (PMS), a proprietary color space used in a variety of industries, including printing and paint, fabric and plastic manufacturing. The Pantone Color Matching System is a standardized color reproduction system, allowing different manufacturers in different locations to refer to name and communicate over 3000 distinct colors.
PANTONE System
One of the best known color specification systems used by designers and printers to communicate color. Available in Coated, Uncoated, and Matte, each swatch book contains a series of colors that can be referenced based on the assigned PANTONE notation.
PDF (Portable Document Format)
A document type created by Adobe® to provide a cross-platform method to display information. Converting a file to PDF format will allow all elements, such as text, graphics or PostScript files, to be accurately represented on any computer system when viewed with the free Adobe® Acrobat® PDF Reader.
Perceptual Rendering Intent
Perceptual rendering tries to preserve some relationship between out-of-gamut colors by compressing the entire tonal range, even if it results in inaccuracies for in-gamut colors. The result is smooth color gradations throughout. Even though perceptual rendering compresses the entire gamut, it remaps the central tones more precisely than those at the edges of the gamut. Perceptual and relative colorimetric rendering are the most useful conversion types for digital photography.
Peripheral
Any external device that can be connected to a computer.
Phase Change Printer
An inkjet printer where the ink starts as a solid but is then heated, liquefied, and sprayed onto a substrate.
Phosphor
A material that emits light when excited by electric charge used in the creation of cathode ray tube display units.
Photochromism
A reversible change in color of a specimen due to exposure to light.
Photoshop (.psd)
The proprietary Adobe® Photoshop® file format that supports all of the application’s features, including layers, masks, channels. This file format may not be able to be accessed by other applications.
Photopic Vision
Adjective used to describe vision mediated by the cone receptors in the retina of the eye, which give rise to the sensation of color occurring at high and medium levels of luminance.
PICT (.pct)
A bitmap, up to 32-bit color file format originally designed to support graphics applications operating on the Apple® Macintosh® platform. This file format is supported by various applications and is commonly used to transfer files between applications. This file format can utilize JPEG lossy compression schemes.
Pigment
A type of colorant consisting of particles made up of many synthetic dye molecules or carbon black; generally more stable than dyes of the same color. Pigmented inkjet inks are credited with better longevity and may have a narrower color gamut.
Pixel
The individual dots that are used to display an image on a computer monitor. The number of pixels defines the image size and resolution.
Pixel Depth
The amount of data used to describe each colored dot on a computer screen. For instance, a pixel depth equal to one means that only black and white colors could be displayed; with a pixel depth equal to four, sixteen different colors could be displayed.
Planographic
In printmaking, a surface that has ink on its flat plane as opposed to being engraved or embossed to hold ink.
Plate (Impression) Cylinder
A cylinder that carries the paper during printing on some presses and offset presses. This cylinder operates differently from one printing process to another.
Platen
The glass surface of a flatbed scanner on which reflective art is placed for scanning.
Plug and Play
The ability of an operating system to identify and configure the system to incorporate peripherals.
Plug-in Module
Third-party software that is loaded into the Photoshop® plug-ins folder and is accessible from a Photoshop menu.
PMT (Photomultiplier Tube)
A light-sensing device usually found in drum scanners. These vacuum tubes are much more sensitive to light than CCD chips.
PNG (Portable Network Graphics)
A bitmap, 24-bit color file format that utilizes lossless compression, originally designed as an alternative to the GIF format for transfer and display of images online.
Portrait (Mode)
The orientation of an image that is taller (horizontal) than it is wide (vertical). Also, a setting controlling an output device to properly fit a computer document to the print medium.
Postcoat
Clear material applied as a final coat to protect prints or artwork.
Posterization
The conversion of an image to a more elementary form by reducing the number of tonal values, creating a surrealistic, stark result.
PostScript
The page description language created and licensed by Adobe® that is used to display and print fonts and images.
ppi (Pixels Per Inch)
The unit that is used to measure the resolution of a bitmapped image.
Preflight
The process of checking a job for possible problems, such as missing fonts and pictures, or incompatible color systems, prior to entering the job into a workflow.
Prepress
The process of getting a job ready to be printed on press, including text layout and color separations.
Primary Colors
Colors, usually three, which are combined to produce the full range of other colors within a color model. All non-primary colors are mixtures of two or more primary colors. Red, Green, and Blue are the primary colors of the additive color model. Cyan, Magenta, and Yellow are the primary colors of the subtractive color model.
Print Density or Optical Density (OD)
The visually perceivable and measurable absorption of light on the surface of a medium due to the presence of a colorant. OD only measures the surface density of a dry hardcopy, not the density of the total amount of ink that was sprayed onto the medium.
Print on Demand
An ability of digital printing to consistently produce prints individually or sporadically over an extended period of time, allowing orders of a small number of prints when needed.
Print Permanence
The resistance of a print to physical change of any type and any source, such as light, heat, acids, etc.
Print Service Provider (PSP)
A commercial, digital printing agency or firm that takes an artist's image file and prints it to the artist's specifications.
Printer Driver
Printer-specific software that allows a computer to communicate with the printer. (See also RIP)
Printer Profile
Using the printer profile, the color management system translates the image's colors to the printer's color space, so the colors appear correctly in print.
Process Color Printing
Printing using the three primary color inks (Cyan, Magenta, and Yellow) plus Black.
Profile
Describes how a device sees color by characterizing an input device, output device, or color space, according to ICC standards. Profiles describe the color attributes by defining a mapping between the device source or target color space and a profile connection space, either CIELAB (L*a*b*) or CIEXYZ. Every device that captures or displays color can have its own profile. The ICC standard provides for profiles in RGB format for scanners, digital cameras, and monitors; in CMYK format for printers and proofers; and in multi-color format for multi-color printing processes.
Profile (Photography)
In a photographic workflow, a color profile describes how a device reproduces color. Custom profiles are created using color management software for each device in the workflow – cameras, monitors, tablets, phones, projectors, and printers.
Profile (Projector)
The color management system translates the image's colors to the projector's color space, so the colors appear correctly when it is displayed on a screen.
Profile (Scanner)
A scanner profile describes the conversion of the scanner specific RGB space to the CIELab system. The testchart determines which colors form the original will be converted to which RGB colors of the scanner. However, since a testchart only covers part of the scanner's entire gamut, it is the profiling software's job to supply a description of those colors that are in the outer areas of the device gamut.
Profile (Tablet)
The color management system translates the image's colors to the tablet’s color space, so the colors appear correctly when it is displayed on screen.
Profile (Video)
In a video workflow, a color profile describes the process of creating a specific look (LUT) for the video footage.
Profile Editing
Programs that enable users to “tweak” ICC profiles for a better subjective color match.
Proof
A prototype that shows the printer and customer what the job will look like after printing so any necessary changes can be made before the job goes to press. Proofs of individual photos are known as scatter or loose proofs. Proofs of pages are called page proofs. Proofs showing how multiple pages are arranged on a large press sheet are known as imposition proofs.
Proofer
A device used to show what a printed job will look like before it goes to press.
Psychophysical
A term used to describe the area of color science which deals with the relationship between physical description and the sensory perception resulting from them.
Purity
The degree to which a color is saturated.
Q
Quadtone Inks
Special multi-monochromatic (B&W) inks.
Quark
Page layout software for design and publishing professionals.
Queue
A series of tasks or operations waiting to be performed by a computer or peripheral device.
QuickTime
A video and sound playback application developed by Apple® Computer.
Quick-set (Quick-drying) Ink
Has a much faster cure than the conventional inks; contains a certain proportion of solvent that is rapidly absorbed by the paper to accelerate drying.
R
Radiant Energy
A form of energy consisting of the electromagnetic spectrum, which travels at 299,792 kilometers/second (186,206 miles/second) through a vacuum, and more slowly in denser media (air, water, glass, etc.). The nature of radiant energy is described by its wavelength or frequency, although it also behaves as distinct quanta (corpuscular theory). The various types of energy may be transformed into other forms of energy (electrical, chemical, mechanical, atomic, thermal, radiant), but the energy itself cannot be destroyed.
Raster Image
An image composed of lines of pixels in a grid layout or bitmap.
Rasterization
The conversion of vector image information to raster image information.
RAW
A file format that allows the user to specify the file type, file creator, and header information and supports up to 48-bit color information with no compression. Due to the amount of information and knowledge required to use this format, novices seldom use it.
RC (Resin Coated) Paper
A term used for photographic paper used in most color and some black-and-white printing applications that has a polyethylene coating on each side.
Receptor Coating
A chemical layer adhered to the surface of a media that receives and binds the ink from the printhead nozzle.
Reel
A big roll of paper used on printing presses.
Reference
In evaluating color difference, the reference is the color against which all measurements are compared. Also referred to as Standard.
Reflectance
The measure of light that is reflected off of a surface and varies according to the wavelength distribution of the light.
Reflectance, Specular
Mirror-like reflectance. The magnitude of the specular reflectance on glossy materials depends on the angle and on the scattering of the light by an uneven surface.
Reflectance, Total
Reflectance of radiant flux reflected at all angles from the surface, thus including both diffuse and specular reflectances.
Reflection
The process by which incident light leaves a surface or medium from the side on which it is incident.
Reflective Scan
The process used to scan a subject that does not allow light to pass through it, such as a piece of paper.
Refresh Rate
The number of times per second that a monitor draws data.
Register
To align the layers of a CMYK separation so all layers are printed exactly on top of each other for proper printing.
Registration Marks
The guidelines on the sides of each layer of a CMYK separation to ensure proper registration or alignment.
Relative Colorimetric Rendering Intent
A rendering intent that maintains a near exact relationship between in-gamut colors, while out-of-gamut colors are clipped to the nearest reproducible hue. The color data lost using relative colorimetric rendering is irreversible. Relative colorimetric is commonly used for logos, solid colors and vector colors.
Relief Process
In printmaking, a process using printing plates that are incised, etched, or sand-blasted before the surface is inked. Lines or areas that have been cut away do not print. The ink is transferred from the surface of the plate to the paper either by hand-rubbing or with a press.
Removable Storage Media
A storage device that can be removed and inserted into any similar playback device.
Render
The process of building a 2D image from the data contained in a 3D scene.
Rendering
The application of color shading or shadows to a computer image to make it more realistic in appearance.
Rendering Intent
When the gamut of source color space exceeds that of the destination, saturated colors are liable to become clipped (inaccurately represented), or more formally burned. The color management module can deal with this problem in several ways. The ICC specification includes four different rendering intents: absolute colorimetric, relative colorimetric, perceptual, and saturation.
Resolution (Res)
The amount of detail in spatial or color variation that can be identified in an image. Refers to the number of smallest discernable dots or pixels.
Resampling
Changing the resolution of a bitmap without changing the file size.
Retouching
The manual or digital process of removing imperfections or unwanted portions of an image.
RGB (Red, Green, Blue)
A color model composed of the primary additive colors of light, which can be mixed to obtain all other colors.
RGB Printer
Printers that use Red, Green and Blue ink to reproduce images on media, generally driven by a manufacturer’s driver and set up to only accept RGB data.
RGB True Color
An RGB color system with 24-bits per pixel color resolution to give a choice of over 16 million colors per pixel. Such a system is generally known as a true color or full color system.
RIFF (Raster Image File Format)
A file format used to store grayscale images.
RIP (Raster Image Processor)
Considered the “brains” of your digital output device, the RIP mathematically converts digital graphics files into information that a printer can use to create images. In addition to processing, most RIPs have been customized to meet the requirements of specific printer types and their users. RIPs can handle layout, color control, archiving and other operations.
ROM (Read-Only Memory)
A type of memory that can be read but not altered in any way.
Rosettes
The pattern created in a printed image when color halftone screens are placed at conventional screen angles.
S
Sampling
A primary way in which analog information is digitized by periodically measuring the analog information.
Saturation
The attribute of color perception that expresses the degree of departure from a gray of the same lightness; grays have no saturation.
Saturation Rendering Intent
A rendering intent that tries to preserve saturated colors, and is most useful when trying to retain color purity in computer graphics when converting into a larger color space. If the original RGB device contained pure (fully saturated) colors, then saturation intent ensures that those colors will remain saturated in the new color space, even if this causes the colors to become relatively more extreme.
Scale
To enlarge or reduce an image by increasing or decreasing the number of scanned pixels or the sampling rate relative to the number of samples per inch needed by the printer or other output device.
Scan
The process of converting an optical image into digital data.
Scanner
A hardware device for capturing an optical image as digital data.
Scattering
Diffusion or redirection of radiant energy encountering particles of different refractive index. Scattering occurs at any such interface, at the surface, or inside a medium containing particles.
Scotopic Vision
Vision mediated by rods alone at very low levels of illumination; night vision.
Screen
A process used to produce halftone dots.
Screen Capture
Capturing what is currently displayed on a monitor.
Screen Printing
Stencil-based impact printing technology.
Screen Resolution
The number of distinct pixels that can be displayed in each dimension of a monitor or television.
Selection
Isolating a portion of a digital image in order to perform additional work or protect the selected area from manipulations applied to the remaining "unprotected" areas.
Separation
Splitting continuous tone images into separated CMYK components for printing.
Separations Color
Any color in a document that needs to print as a separate plate on a printing press.
Shading
Coloring a surface according to its incident light ; the color depends on the position, orientation and attributes of both the surface and the sources of the illumination.
Shadow Detail
Subtle features in the darker part of an image.
Shadow Point
The darkest tone printable in an image without being black. All tonal values below this threshold will print as black with no detail.
Sharpening
An image enhancement technique in which the contrast between specific pixels is enhanced.
Sheet-Fed Press
A printing press fed with sheet media instead of rolled substrates.
Show-Through
Occurs when ink penetrates the paper substrate and is visible from the back; also termed "print-through."
Side Guide
A system on the left or right of the press that immobilizes the sheet to keep it in position during printing.
Silhouetting
Masking or image blocking to isolate an image from the background.
Simultaneous Contrast
The phenomenon that occurs when the surrounding color influences how a color is perceived.
SLR (Single Lens Reflex)
A form of small format (35mm or 6cm) camera that has a reflecting mirror that retracts when the shutter is released. An SLR allows the photographer to view the image exactly as it will be framed in the photo.
Soft Proof
Viewing a digital image with a monitor instead of generating a hard copy proof. It is very important that the display used for soft proofing is calibrated to ensure colors are accurately represented.
Solid Ink
Solid ink technology involves the use of solid, resin-based ink. The printhead and ink supply are heated to melt the ink and bring it to very low viscosity. The ink is ejected hot and "freezes" on the surface of the medium or onto a drum from which it is transferred like an offset press, onto paper. Solid ink technology can be printed and transferred, or can be printed directly. Also called "phase change."
Spatial Resolution
The smallest feature of an image that can be detected as a fraction of the total image.
Specifications for Web Offset Publications (SWOP)
American standards specifications for printing on offset presses.
Spectral
Pertaining to the visible spectrum, thus, having to do with color.
Spectral Data
Method for uniquely identifying an object based on each wavelength of light is reflected from it.
Spectral Power Distribution (SPD)
Graphical or numerical representation of radiant energy per unit interval of wavelength for a given light source.
Spectral Reflectance Curve
The spectral reflectance curve graphically depicts the color composition of an object. The x-axis shows the wavelengths, starting with 380nm and ending with 700nm, and the y-axis shows the relative reflectance (the amount of light reflected from the object in %).
Spectrophotometer
A device that measures light reflectance across the visible spectrum, from approximately 380–720 nm wavelengths. This very precise data can then be converted into densitometric or colormetric data. The spectrophotometer is the most useful measurement device because it can be used for density calibration as well as ICC profiling.
Spectrophotometric Curve
A curve measured on a spectrophotometer; a graph with relative reflectance or transmittance (or absorption) as the ordinate, plotted with wavelength or frequency as the abscissa.
Spectrum
The spatial arrangement of components of radiant energy in order of their wavelengths, wave number, or frequency; in this context, the full range of visible wavelengths of light energy radiation.
Specular
The highlight of an object with a shiny surface.
Specular Component Excluded (SCE)
Measurement of reflectance made in such a way that specular reflectance is excluded from the measurement; diffuse reflectance only.
Specular Component Included (SCI)
Measurement of the total reflectance from a surface, including the diffuse and specular reflectance.
Specular Gloss
Relative luminous fractional reflectance from a surface in the mirror or specular direction.
Specular Highlight
The small highlight area of an image that contains little to no detail.
Specular Reflection
Reflectance of a beam of radiant energy at an angle equal but opposite to the incident angle; the mirror- like reflectance.
Specular Reflectance Excluded (SCE)
Measurement of reflectance made in such a way that the specular reflectance is excluded from the measurement; diffuse reflectance. The exclusion may be accomplished by using 0 (perpendicular) incidence on the samples. This then reflects the specular component of the reflectance back into the instrument by use of black absorbers or light traps at the specular angle when the incident angle is not perpendicular, or in directional measurements by measuring at an angle different from the specular angle.
Specular Reflectance Included (SCI)
Measurement of the total reflectance from a surface, including the diffuse and specular reflectances.
Spot Colors
Spot Colors, such as PANTONE®, are ink colors that are selected from a specification book and cannot usually be represented with CMYK. Each color is mixed and placed in a printing unit on the press. Spot color inks are cost-effective for two- or three-color printing and may also be used for colors that process printing cannot adequately produce. Use spot color inks when you need three or fewer colors and you will not be reproducing process-color photographs, or you want to print logos or other graphic elements that require precise color matching.
sRGB
One of several standard RGB color working spaces. Best used for images on the Internet.
Standard Illuminant
The relative energy emitted by a real or imaginary light source that is mathematically defined at each wavelength across its spectral distribution.
Standard
In evaluating color difference, the standard is the color against which all measurements are compared. Also referred to as Reference.
Standard Observer (1931, 2 Degree Observer)
The 2 degree visual field observer is the standard observer recommended by the Commission International de l’Èclairage (CIE) in 1931. This is based on the results of a color matching experiment that used a 2 degree field of view.
Stochastic Screening
A print screening process in which uniformly-sized dots are placed to appear random in order to create the illusion of tone levels. Also called FM screening.
Stop Face
The place on the feed table where the sheets are immobilized before being supported by the cylinder clamps to ensure an always equal side register.
Stylus
A tool that is used on a graphic input tablet as a drawing instrument, or as a mouse.
Subsampling
Scanning at a less-than-optimum sampling rate.
Substrate
A material that receives a printed image, dye or colorant.
Subtractive (Reflective) Color
Subtractive color systems, like printing, work by removing selected colors of light reflected off or transmitted through them. The subtractive primary colors are the opposite of the additive primaries; that is, Cyan (minus Red), Magenta (minus Green), and Yellow (minus Blue). Subtractive secondary colors include Red (Magenta plus Yellow), Green (Cyan plus Yellow), and Blue (Cyan plus Magenta). The subtractive tertiary color is Black (Cyan plus Magenta plus Yellow).
Subtractive Color Mixture
Colorant mixture which must take into account both the absorption and scattering of two or more of the individual pigments used in the mixture.
Subtractive Primaries
Cyan, magenta and yellow. Theoretically, when all three subtractive primaries are combined at 100% on white paper, black is produced. When these are combined at varying intensities, a gamut of different colors is produced. Combining two primaries at 100% produces an additive primary, either red, green or blue.
Supplemental Observer (1964, 10 Degree Observer)
The 10 degree visual field observer is the supplementary observer adopted by the Commission International de l’Èclairage (CIE) in 1964. This is based on the results of a color matching experiment that used a 10 degree field of view.
Surround
Portion of the visual field immediately surrounding the central field or pattern of interest.
SWOP (Standard Web Offset Printing)
The standards that define the color and dot gain characteristics of a web press.
T
Target
Whether visually or with color management software, target images provide a range of color and grayscale for calibrating monitors, printers, scanners, and digital cameras.
Testchart
Collection of color patches that are used to generate ICC profiles for input and output devices. Testcharts are provided on paper or transparent materials, and also as files.
Thermal Inkjet Printer
Printer using inkjet print heads with a heat (thermal) system used to produce the ink drop.
Thermal Transfer Printer
A machine that digitally prints by transferring inks (resin or wax based) from a foil or ribbon onto media such as paper or vinyl.
Thermochromism
A reversible change in color of a specimen due to change in temperature of the specimen. This is typical of highly saturated (vivid) colors (such as bright reds, yellows, and oranges).
Third Party Software
Software that is either freely distributed or sold by an entity other than the original vendor of the development platform.
Thumbnail
A small version of a larger graphic image used for indexing databases of images or to preview a very large image.
TIFF or TIF (Tagged Image File Format)
The standard file format used for most digital imaging programs. TIFF is a highly extensible format that allows image data to be tagged with additional information through an image file directory (IFD), which contains header-type information without actually being a part of the file's header. TIFF can be used for black-and-white, grayscale, RGB, and CMYK images. TIFF can be uncompressed or may use any of a variety of compression methods, though TIFF most commonly uses LZW compression. It is probably the most versatile file format.
Tiling
The process of breaking down an image into sections for editing or printing purposes.
Tint
To mix white pigment with absorbing (generally chromatic) colorants. Also, the color produced by mixing white pigment with absorbing (generally chromatic) colorants. The resulting mixture is lighter and less saturated than the color without the white added.
Topcoat
The coating applied to the surface of inkjet or other type media during the manufacturing process. The topcoat enhances ink adhesion and other performance characteristics and helps to control dot gain, drying time, and moisture resistance.
Tone Curves
A curve describing the relationship between the input values and output values for brightness or color that can be used to adjust the contrast of the image.
Toner
A dry, powdery pigment used by printers and copying machines that contains a colorant, an electrostatic thermoplastic, a charge-control agent, and often a magnetic material.
Total Color Difference (∆ or Delta E)
A single number that expresses the magnitude (size, degree, or amount) of a difference between two colors. The value tells nothing about the nature of the color difference.
Total Ink Coverage
In CMYK printing, it is often important to limit the amount of ink on the page to avoid long drying times, smudging, and excessive ink usage. When making UCR or GCR separations, the total amount of ink in a particular area can be quantified as total ink coverage, on a scale of 0 – 400%. 100% of C, Y, M and K equals 400%. Using UCR and GCR, total ink coverage in CMYK printing is typically limited to 200 - 320%.
Total Reflectance
Reflectance of radiant flux reflected at all angles from the surface, thus including both diffuse and specular reflectances.
Transmissive Scan
A transmissive scanner allows light to pass though a transparent or translucent object, such as a negative or slide.
Transform
The mathematical conversion from one color space to another, such as RGB to CMYK.
Translucent
Diffuse transmission of light. No clear image can be seen.
Translucency
Appearance state between complete opacity and complete transparency; partially opaque.
Transmission
Process by which incident light is transmitted through a material or object.
Transmittance (of Light)
That fraction of the emitted light of a given wavelength which is not reflected or absorbed, but which passes through a material or object.
Transparent
Adjective to describe a material that transmits light with minimal diffusion or scattering. Clear, not opaque.
Trapping
A prepress technique that allows slight variations in registration during the press run.
Tristimulus
Of, or consisting of, three stimuli; generally used to describe components of additive mixture required to evoke a particular color sensation.
Tristimulus Values
Amounts (in percent) of the three components necessary in a three-color additive mixture required for matching a color; in the CIE System, they are designated as X, Y and Z. The illuminant and standard observer color matching functions used must be designated; if they are not, the assumption is made that the values are for the 1931 observer (2 degree field) and Illuminant C.
True Color Image (24-bit color)
A digital color model that uses eight bits of each of the three additive colors (Red, Green and Blue), and can reproduce 256 shades of each. Each pixel has 24 bits assigned to it, representing 16.7 million colors. 8-bits - or one byte - is assigned to each of the red, green, and blue components of a pixel.
True Color
The common name for a 24-bit color.
True Color Image (24-bit color)
A digital color model that uses eight bits of each of the three additive colors (Red, Green and Blue), and can reproduce 256 shades of each. Each pixel has 24 bits assigned to it, representing 16.7 million colors. 8-bits - or one byte - is assigned to each of the red, green, and blue components of a pixel.
Turbidity
Reduction of transparency of a specimen due to the presence of particulate matter.
TWAIN
An industry-wide standard for devices such as scanner and digital cameras to interface with software programs.
U
Ultraviolet
Radiant energy below 380 nm; portion of the electromagnetic spectrum between about 10 and 380 nm.
Ultraviolet (UV) Brightener
Dyes that absorb ultraviolet radiation and re-radiate a portion of UV as visible light in the blue region of the spectrum. This makes paper appear brighter and less yellow. UV reflectance cannot be detected by the human eye, but papers with a lot of brightener can be detected with a black light or a spectrophotometer.
Ultraviolet (UV) Ink
Ink that contains acrylic derivatives and photoinitiators to trigger the drying process when the ink is exposed to ultraviolet rays.
Ultraviolet (UV) Light
Radiant energy with wavelengths slightly shorter than the visible spectrum.
Ultraviolet (UV) Protective Glaze
An acrylic sheet used in framing art that has ultraviolet light inhibitors capable of filtering out 99 percent of UV rays; one of the causes of print fading.
Ultraviolet (UV) Resistance
The resistance of something to change under UV light sources, including daylight.
Under Color Removal (UCR)
The process of eliminating equal amounts of Yellow, Magenta, and Cyan from the neutral shadow areas and replacing them with black ink in the black separation. Compare to GCR.
Uniform Chromaticity Scale Diagram
Any one of a variety of transformations of the CIE chromaticity diagram on which all pairs of just noticeably different colors of equal luminance are represented by pairs of points separated by nearly equal distances.
Uniform Color Space
A color space in which equivalent numerical differences represent equivalent visual differences, regardless of location within the color space. A truly uniform color space has been the goal of color scientists for many years. Most color spaces, though not perfectly uniform, are referred to as uniform color spaces, since they are more nearly uniform when compared to the chromaticity diagram.
Unsharp Masking (USM)
A process used to sharpen images.
Unzip
To decompress a file.
Upload
To send a file to a networked host or to another machine.
V
Value (in Munsell)
An attribute of color used in the Munsell color system to indicate the lightness of a specimen viewed in daylight, on a scale from 0 for the ideal black to 10 for ideal white, in steps that are visually approximately equal in magnitude.
Variable Data Printing
A digital printing application in which documents can be customized during the printing process using data from a database of images or text.
VCD (Video CD-ROM)
A full motion digital video format on CD-ROM using MPEG-1 video compression and incorporating a program control bar with controls similar to those of a VCR.
Vector Image
An image represented by mathematically defined shapes, such as lines, polygons, text, and groups of objects as opposed to bitmaps of them; also referred to as line-drawing graphics.
VGA (Video Graphics Array)
A display standard providing 640 x 480 resolution with 16 colors.
Viewing Booth
Color is affected by the type of light in which it is viewed and surrounding colors. A viewing booth provides an environment that conforms to standard viewing conditions and allows you to simulate a variety of different lighting environments for color-critical work.
Virtual Memory
A type of hard drive space that mimics actual memory (RAM).
V-RAM (Video Random Access Memory)
A special type of RAM that can perform reads and writes at the same time, allowing it to send information to the monitor at the same time it receives new information from the video processor.
Visual Spectrum
That portion of the electromagnetic spectrum between 380 nm and 700 nm that can be seen by the human eye.
Volume of Acceptability
The volume of acceptability is used to represent the location of acceptable trials in that color space. It is a three-dimensional region that surrounds a standard and is defined by tolerance values. If a trial falls within this volume, it is acceptable according to the tolerance criteria. If it falls outside this volume, it is unacceptable according to the tolerance criteria.
VRML (Virtual Reality Modeling Language)
A programming language that supports animation of virtual spaces on web pages.
W
.wav
A sound file format used for storage and transmission of audio files denoted by the file extension .wav.
Wash Up
To clean the ink system and damping system when changing ink colors.
Watermark
A faint background image on a printed piece or included in digital files as a security feature (such as on printed currency or checks) or to denote a copyright of an image. An identifying mark or symbol embedded in the substrate on which the art is made, usually referring to the maker of the substrate.
Wavelength
The distance between the crests of two adjacent waves.
Web Press
A high-speed printing press that prints on both sides of a continuous roll of paper. Web presses are used for high-volume printing such as newspapers and magazines.
White
The result of combining the additive primary colors (Red, Green, and Blue). In the subtractive color mixing system, white is the result of the absence of any color.
White Balance
The balancing of color components to create pure white when photographing or scanning a white object; a substitute for a color temperature setting.
White Point
The color and intensity of a device's brightest white. With printers, this is usually the white of the paper. With scanners, the color that when scanned produces values of 255, 255, 255 (RGB). Ideally, the white point is 100 percent neutral reflectance or transmittance.
White Reflectance Standard
A physical white standard of an imperfectly diffusing material, such as white ceramic, that is calibrated in reference to the perfect diffuser.
Whiteness
Attribute by which an object color is judged to approach the preferred white.
Wide Band Fluorescent
Generic term given to those fluorescent lamp products such as Cool White and Warm White that produce wide bands of visible light as a function of their phosphor blend.
Wide Area Network (WAN)
A network that covers a wide geographical area and usually operates at speeds lower than local area network (LAN) speeds.
Working Space
Working spaces provide a common color space in which to connect workflows for accurate color matching between input and output.
WYSIWYG
“What you see is what you get” is a display interface that accurately represents on a monitor how fonts and images will appear when printed.
X
X
One of the three CIE tristimulus values - the red primary.
XGA (Extended Graphics Array)
An IBM standard display mode providing 1,024 x 768 pixels of spatial resolution and 256 colors.
XML (Extensible Markup Language)
A subset of SGML whose objective is to enable SGML to be served, received, and processed on the Web just as HTML.
XYZ
The set of tristimulus values for numerically describing a color, calculated using ASTM E308-85.
xyY (Chromaticity Coordinates)
A non-uniform color space in which colors are located within a three-dimensional rectangular coordinate system; x and y describe the chromaticity (hue and chroma) of a color. Y describes the luminosity (lightness or brightness) of a color.
Y
Y
One of the three CIE tristimulus values, equal to the luminous reflectance or transmittance - the green primary.
Z
Z
One of the three CIE tristimulus values - the blue primary.
Zebra Stripes
Feature that allows you to see where certain areas of brightness in the frame may be "blown out," or too bright. When this happens at a certain level, the Zebra Stripes show up on that area to indicate that it may be too bright. These Zebra Stripes are just a series of black stripes that move in a distracting pattern, and though you may never have heard them referred to as this you will likely find them familiar.