Glossary of Terms



Adaptive palette:
Image-specific set of colors chosen to most closely represent those in the original source. Part of a custom color look-up table.

Additive Colors:
Red, Green, and Blue are referred to as additive colors. Red+Green+Blue=White.

Adobe Systems, Inc:
A software applications company located in Mountain View, CA, known for Photoshop™, TypeManager™ and Illustrator™.

The specific process in a computer program used to solve a particular problem.

An effect caused by sampling an image (or signal) at too low a rate. It makes rapid change (high texture) areas of an image appear as a slow change in the sample image. Once aliasing occurs, there is no way to accurately reproduce the original image from the sampled image.

Alpha Channel:
An additional 8bit channel, used by some editing software for masking or additional editing applications.

The process of reducing stair-stepping by smoothing edges where individual pixels are visible.

Apple Talk:
The Local Area Networking system introduced by Apple Computer.

The basic design of a computer system, its circuitry, microprocessor, memory, etc., and its connectivity of components.

Long-term storage of data or images. Archiving is generally accomplished on some form of magnetic media; such as disk or tape, or optical media; such as Writable CD.

Information from a JPEG image that is misinterpreted. color faults that visibly show up in the image.

Array Camera:
A digital camera that uses a large CCD chip (an array of rows and columns of light sensitive pixels) to sense the entire image at one time as opposed to scanning the image one row of pixels at a time.

Array Processor:
A portion of large computer system that assists processing data fast. Several Operation simultaneously.

Visual effects introduced into a digital image in the course of scanning or compression that do not correspond to the image scanned.

Artificial Intelligence:
The use of computers to solve problems the way human being does.

An acronym for the American Standard Code for information Interchange, which converts keyboard input into digital information. It covers all the printable and control characters with a system consisting of 128 seven-bit patterns for printable characters

Aspect ratio:
In computer graphics, the images' relationship of width to height must be kept the same when it is displayed on several screens.

Adobe utility program that improves a computer monitor's display of type at any size.

A Generic term used to deal with animation, audio and video.


Background processing:
Concurrent processing work performed by the computer to carry out the investigative instructions of the operator while other activities are being performed.

An artifact of color gradation in computer imaging, when graduated colors break into larger blocks of a single color, reducing the "smooth" look of a proper gradation.

The transmission capacity of a communications channel, usually expressed in bits or bytes per second (the former is also called baud rate).

Barrel Distortion:
Image distortion that spread the center dimensions of the image.

Base resolution:
The Photo-CD image resolution [512x768 pixels] formatted to be displayed on TV.

4 Base:
The 1536 x 1024 pixels image ideal for high definition TV.

16 Base:
The 2048 x 3072 pixels image suitable for digital Imaging.

64 Base:
Max resolution for Photo-CD The 4000 x 6000 pixels image produces a 72 MB image File.

Batch Processing:
A Method that allows for repetitive processing of groups of data by executing only one command.

Baud rate:
The speed at which computer data can be transmitted via modem. Example: Modem rates may be 1200, 2400 and 9600 baud. To determine the number of bytes transferred per second - divide the baud rate by 8.

Bulletin Board System, a system that allows Computer 2 computer communication via modem to exchange and copy files.

Bezier curve
A mathematically defined curve made up of four points, two ends and two in between, that affect its shape.

Bi-cubic interpolation:
A Matrix for comparison of central pixels to surrounding pixels.

A coding or counting system with only two symbols or conditions (off/on, zero/one, mark/space, high/low). The binary system is the basis for storing data in computers.

A binary digit, a fundamental digital quantity representing either 1 or 0 (on or off).

Bit Depth:
The amount of tone data per sample expressed in number of bits. Typical bit depths are 1 for line art, 8 for grayscale and 24 for color images. If the number given for bit depth is greater than 16 and is not divisible by 3 then it is probably referring to 4 channel CMYK.

An image made up of dots, or pixels. Refers to a raster image, in which the image consists of rows or pixels rather than vector coordinates.

Stair-stepping of shades in a gradient or on the blend.

When a picture extends to the extreme edge of a page it is said to bleed. A full page bleed has an image covering the entire page with no borders. In order to give the printer some leeway in trimming a page with a bleed image you need to provide an image that extends beyond the crop marks. This extra area is called bleed and is usually 1/8 or 1/4 inch.

Beyond the cutting-edge of technology. A company that is accustomed to working in the experimental fringes out beyond the cutting-edge is very capable of producing work that is state-of-the-art.

The art of softening the detail of a digital image. The process can be applied selectively to portions of an image.

Automatically locating the correct edge of an image on a scan so that marking from the edge, frame, etc. is not captured.

The value of a pixel in an electronic image, representing its lightness value from black to white. Usually defined as brightness levels ranging in value from 0 (black) to 255 (white).

Bubble Jet:
See Ink Jet

A special area set aside either in hardware or software for temporary. Usually, the bigger the buffer, the faster the computer can process other data.

Combining two or more different functions into one expansion board or peripheral device. Also combining software "bundled" with hardware.

An ensemble of eight bits of memory in a computer.



A temporary storage area for information which locates itself between the hard disk and the RAM by employing intuitive logic. It also speeds up the access time of the data.

The act of adjusting the color of one device relative to another, such as a monitor to a printer, or a scanner to a film recorder. Or, it may be the process of adjusting the color of one device to some established standard.

The entire image displayed on the monitor, but not necessarily at full resolution.

A digital camera is said to Capture an image rather than Take a picture.

Charged-Coupled Device. A light sensitive electronic device that emits an electrical signal proportional to the amount of light striking it. Used in scanners and video cameras.

CCD array
A device that mounts many CCDs together to allow for capture of many pixels at the same time.

Compact Disc-Read Only Memory. A CD-ROM drive uses the CD (compact disc) format as a computer storage medium. One CD can store 640 megabytes of data and other mixed media on a disc about the size of a traditional 5-1/4-in. floppy disk.

Compact Disc Recordable writes data to discs, which can then be read by standard CD-ROM drives.

Computer Graphics Metafile. An image file format designed to handle a wide range of image types, but currently used primarily for vector graphics.

The process of building a Look-Up-Table (LUT) for a calibrated monitor. By profiling the output of numerous key colors from a monitor a LUT can be created that allows the computer to substitute corrected (Characterized) colors to achieve consistent and accurate output.

CIE (Commission International l'Eclairage):
An international standard committee that defined the de facto standard color model used in all color management systems.

Client/Server Architecture:
A systems architecture design that divides functions (which might be part of a single application) between two or more computers. The client is the machine that requests information; the server is the machine that supplies it. A typical client/server architecture for imaging might allow a server to store and transmit a compressed file, and the client to decompress, process, and display the image.

Clipping Paths:
Vector defined outlines used to silhouette an object. They are created from ``Bezier" curves and are ideally suited in describing the hard edge outlines of mechanical or man-made objects. A clipping path is a particular type of path that instructs the RIP to ignore any part of the image outside of the path. If you want to place a file over another object or background in a page layout program such as Quark-Xpress then you will have to use a clipping path to eliminate the white that surrounds the image.


Color Lookup Tables - A color referencing system

Color Management System.
A comprehensive hardware/software solution of maintaining color fidelity of an image from scanner to monitor to printer.

CMY (Cyan, Magenta, Yellow):
The three subtractive color primaries.

CMYK (Cyan, Magenta, Yellow, Black):
One of several color encoding system used by printers for combining primary colors to produce a full-color image. In CMYK, colors are expressed by the "subtractive primaries" (cyan, magenta, yellow) and black. Black is called "K" or keyline since black, keylined text appears on this layer.

Color Cast:
The effect of one color dominating the overall look of an image. Often caused by improper exposure, wrong film type, or unusual lighting conditions when shooting the original image. Also caused, when scanning, by the sometimes unpredictable interaction between an image and a scanner.

Color curves:
A mechanism for controlling color changes, and matching colors. Color curves are set by user-adjustable lookup tables that define a color transform, which may be applied to each primary additive or subtractive color in the image.

Color Gamut:
Any color medium representing its own range of color, including film, a monitor, printed images or the human eye.

Color proof:
Proofs may be in-house for checking composition, or a representation of the final print for client OK. Common types are CromalinTM, MatchPrintTM, inkjet, dye sublimation and laser copies.

Color Separation:
An image that has been converted or "separated" from RGB into the four process colors. See CMYK.

There are numerous methods of creating or describing a specific color and tone. These different models are called Colorspaces. examples are RGB, CMYK, LAB, YCC.

Composite (Comp):
A term for combining images, artwork, lineart and type.

The reduction of data to reduce file size for storage. Compression can be "lossy" (such as JPEG) or "lossless" (such as TIFF LZW). Greater reduction is possible with lossy compression than with lossless schemes.

Continuous Tone:
Continuous tone images use pixels instead of halftone dots. That is to say that rather than simulating variations in tone by increasing or decreasing the size of closely spaced spots of 100% ink or pigment color a continuous tone (CT) image is able to print or display continuously varying levels of pigment. To achieve the perception of a smooth (continuous) tonal transition from black to white it is necessary to have 256 differentiations of tone from black to white. If you have significantly fewer differentiations the human eye will begin to perceive breaks between the tones which will result in posterization and banding in the gradients.

A measure of rate of change of brightness in an image. ---HIGH contrast implies dark black and bright white content; ---MEDIUM contrast implies a good spread from black to white; ---LOW contrast implies a small spread of values from black to white. Crop: To permanently discard unwanted information in the perimeter area of an image.

Contract Proof:
A proof the printer promises to be able to match on press.(See: Matchprint)

CPU/ Central Processing Unit:
A large chip which holds the "brains" of the computer.



Digital Audio Tape format is a mini tape format for image storage and backup.

The process of returning a compressed file to the full file size.

The setting in a computer program which will take effect if no changes are made.

The measure of light blocking (in the case of transparencies) or absorption (in the case of prints), expressed logarithmically. Typical slides have a density of 3.0 while typical prints have a density of 2.0.

Desktop refers to computer and imaging systems linked to personal computers (PC's) such as Apple Macintosh or Intel Pentium computers as opposed to larger workstation type of computers such SUN or Silicon Graphics. Desktop systems use operating systems such as Macintosh OS, or Windows 95. Workstation systems typically use UNIX or Windows NT

Data Interchange Format, a standard for access between programs.

A system or device in which information is stored or manipulated by on/off impulses, so that each piece of information has an exact or repeatable value (code).

Digital Camera:
A camera that directly captures a digital image without the use of film.

Disk cach
Improves performance of disk controller via high-speed memory.

Camera displacements are a feature of Large Format studio cameras that allow the relationship between the film plane and the lens plane to be altered in order to alter and control the perspective of the image. By using displacements it is possible, for example, to look up at a building and keep the vertical sides of the building parallel without having the keystone effect normally experienced with a camera. Digital cameras do not work well with significant displacements. The control of perspective is often best left to be accomplished in Photoshop

Changing the size of an image in a non-proportional manner. Also known as "anamorphic scaling." Dither - The process of adding dots to a small area in order to smooth out the appearance of an image, or specifying colors to adjacent pixels in order to simulate intermediate colors in a bit mapped image.

A technique of using patterns of dots or pixels to create the effects of an intermediate tonal value. When a monitor cannot display intermediate colors or tones it attempts to achieve the required color by intermixing the two closest colors in a scattering (dithering) of pixels. This occurs most often when you attempt to display a full color image on a monitor with a 256 or a 64,000 color video display board. In an illustration dithering can make typography almost impossible to read.


Strictly speaking a dot is the smallest spot an imagesetter, or printer can output and is usually expressed in dots per inch (dpi). However the term dot is often used interchangeably with Pixels (ppi) or Halftone Cells (lpi or L/S). An imagesetter dot is of a specific and unvarying size. A 300dpi laser printer can only make dots that are 1/300 of an inch in diameter. To make a bigger spot it uses several dots. On the other hand, a halftone dot varies in size in order to simulate continuous tone. (see: Halftone)

Dot Gain:
The effect of ink spread and absorption into paper during printing resulting in darker tones, especially midtones.

The transfer of information from one computer to another. Frequently used to describe file transfer from a network file server to a personal computer.

DPI (Dots Per Inch):
The measurement of resolution of a printer or video monitor based on dot density. For example, most laser printers have a resolution of 300 to 600 dpi, most monitors 72 dpi, most PostScript imagesetters 1200 to 2450 dpi. The measurement can also relate to pixels in an input file, or line screen dots (halftone screen) in a prepress output film.


Dynamic Random Access Memory - a computer memory device offering high data packing density and data rates. Also Dram chips for PCs.

A software utility designed to tell a computer how to operate an external device. For instance, to operate a printer or a scanner, a computer will need a specific driver.

Drop Shadow:
A graphic art effect designed to simulate the shadow cast by three dimensional shapes

Drum Scanner:
A high-end scanning device, utilizing PMT technology, used to digitize prints, transparencies, and artwork.

Acronym for desktop publishing, including typesetting, image handling and page composition

A type of continuous tone printing process that produces a vibrant 300ppi color print. The pixels are printed by a thermal print head that sublimates (vaporizes) the dye from a colored saran wrap like ribbon onto the dye-sublimation paper. The hotter the element on the thermal printing head, the darker the spot of color.

Dynamic Range:
The dynamic range or Optical Density of a scanner is a measure of the range of densities and the deepest shadow density that the scanner can see into and record information. If the dynamic range of the transparency exceeds that of the scanner then the scanner will perceive everything beyond its range as black. A Drum Scanner with a Dynamic Range of 3.8D and a bit depth of 48 will produce a much higher quality, richer, more detailed scan than a Flatbed Scan with a Dynamic Range of 2.5D and a bit depth of 24 at the same scan resolution.



A image, or line art, in whole or part of the page, composite or file.

Elliptical Dot:
A halftone screen dot that can produce better tonal gradations than a circular dot. Emboss - Usually done photo-mechanically, but some EIM & CEPS systems can accomplish the process in seconds.

Coating on the light-sensitive material. The opposite side of the base.

Every computer works within a netware or software surrounding. The condition in which a computer operates. Also, an operating system used to support another operating system is an "environment."

Encapsulated PostScript. A subset of the PostScript page description language that allows any single-page artwork, be it line art or image data, to be saved and placed into any other EPS compatible document.

A networking system providing transfer of data between computer systems and peripherals over a coaxial link.

The process of transporting data from one computer, program, type of file format, or device to another.



The process of merging borders, or softening the edge around a mask.

Fiber optics:
Very thin cables used in transmitting data.

A named collection of binary information stored as an apparent unit on a secondary storage medium such as a computer disk drive. Film Recorder: A device that is used to record a digital image onto photosensitive film.

Film recorder drum:
The highest quality film recorder. They may be sheet- or roll-fed with exposure via white light or laser. It is possible to image on negative or positive film plus photographic print material.

An application that extends or offers unique expansion of a software program. This is a key component of many imaging software programs.

Flash Memory:
A type of memory chip that can retain data after the system has been turned off. Its advantage is that digital cameras with flash memory can have batteries go "dead" and yet retain image data.

Flat Bed Scanner:
An optical scanner in which the original image remains stationary while the sensors (usually a CCD linear array) passes over or under it. The scanned material is held flat rather than being wrapped around a drum.

FPO (For Position Only):
A low resolution image file used for placement in page layout programs. The low-res file is small so that it doesn't slow down the machine and is used for position only. It is swapped out for the high resolution file when the page is RIPíed.

FTP File transfer protocol:
A method of moving or transferring files between computers on the Internet.



GIF File Format :
Stands for Graphic Interchange Format, a raster oriented graphic file format developed by CompuServe to allow exchange of image files across multiple platforms.

GIF89 File Format:
The most recent GIF standard designed for image use on the Internet and on line services.

The measure of the contrast of an image or imaging device.

Gamma Correction:
The measure of contrast that results in lightening or darkening the midtone regions of an image. Also, the amount midtones need to be adjusted on a monitor.

The range of colors and tones a device or colorspace is capable of recording or reproducing. The human eye can sense many more colors than can be reproduced on a computer monitor in RGB colorspace. The human eye has a larger Gamut than the computer monitor.

Gaussian brush:
A brush with variable density.

Gigabyte (GB):
A measure of computer memory or disk space consisting of about one thousand million bytes (a thousand megabytes). The actual value is 1,073,741,824 bytes (1024 megabytes).

GPIB Interface:
Graphic Port Interface Bus - A standard interface in the graphic arts for graphic computers and peripherals.

A smooth spread between colors.

Gray Scale:
A term used to describe an image containing shades of gray as well as black and white.

Graphical User Interface - a computer control system whereby the operator commands the computer with a mouse or stylus.



Slang for a non-professional dedicated computer operator.

Halftone Image:
In order to simulate the reproduction of continuous tone images with ink on paper it is necessary to convert the continuous tone image into a halftone image. Black ink is just To print a gray tone from black we print many closely spaced black dots on white paper. The dots are so small that the eye doesn't see them so what it does see is the mixture of black ink dots and bare white paper between the dots which appears to be gray. A 50% gray would have dots sized so that they covered half of the area with black ink and left half of the area as bare paper.

In order to effectively simulate continuous tone we need to be able to reproduce 256 levels of tone between black and white. So for a halftone image we need to be able to print 256 different sizes of dots. An imagesetter varies the size of the halftone dot by printing clusters of much smaller dots. To print 256 different sizes of halftone dots an image setter divides the area up into halftone cells that are 16 imagesetter dots wide by 16 imagesetter dots high. (16x16=256) If, within the boundaries of this halftone cell the imagesetter prints 128 black dots then you have a 50% halftone dot. So if an image setter is capable of printing 2400 dots per inch then the highest line screen you can output is 150 lines per inch (2400/16=150).

Hard copy:
Refers to a print or proof, as opposed to viewing on a monitor.

High-Definition Television - Approximately double the resolution of "normal" TV.

A vertical bar graph displaying the distribution of the tonal values of the pixels in an image. The X axis represents the tonal value of the pixels (0-255) and the Y axis represents the number of pixels having that tonal value.

Hewlett-Packard Graphics Language.

HTML (Hypertext Markup Language):
An encoding format for identifying and linking electronic documents used to deliver information on the World Wide Web.

A term used to describe the entire range of colors of the spectrum; hue is the component that determines just what color you are using. In gradients, when you use a color model in which hue is a component, you can create rainbow effects.



File storage format used with Kodak's PhotoCD.

Output devise to image onto separation film. They are the preferred PostScript compatible and non-PostScript devices.

Electronic representation of a document, stored and displayed as a bitmap.

Image Processing:
Capturing and manipulating images in order to enhance or extract information. Image Resolution: The number of pixels per unit length of image. For example, pixels per inch, pixels per millimeter, or pixels wide.

Term used to describe both the products and industry dealing with images.

The process of bringing data into a document from another computer, program, type of file format, or device.

Indexed Color:
A type of color file that uses only one channel and assigns one of 256 colors to a pixel. Sort of like Paint-by-Numbers approach to color. The quality is poor...but the files are really small...good for the web.

Ink-Jet Printer:
An inexpensive alternative to a laser printer, an ink-jet printer forms text and images out of dots created by jets of ink. Color ink-jets support many different media sizes and output resolutions.

The technique of estimating the tonal value that lies between two known tone samples. Used for enlarging an existing image. Also used when capturing an image during the scanning process to achieve higher than optical resolution.

Iris printers are extremely sophisticated Ink Jet Printers that spit out droplets of ink that are as small as red blood cells! (1/2000 of an inch) Iris printers are very popular not only as proofing devices but also for making fine arts quality limited editions on specialized papers such as heavy water color stock. These are often called Geclee prints (pronounced ``gee-clay")


A 16-bit bus for PCs.



Another word for stair-stepping or staircased edges of a raster or vector image. This problem can appear when low-resolution files are blown up to large sizes.Jaggies:

JPEG Compression:
A file compression standard established by the Joint Photographic Experts Group that uses a combination of DCT and Huffman encoding to compress images. JPEG is a "lossy" compression algorithm, meaning that it slightly degrades image quality.



An amount of computer memory, disk space, or document size consisting of approximately one thousand bytes. Actual value is 1024 bytes.

Kodak Approval Proof:

A digital proofing method that accurately simulates a halftone proof from a digital file without having to make halftone separation films.



LAN (Local Area Network):
A communications network that's physically connected by cables and confined to a single office or a single building. It enables a group of computers to exchange files and share peripherals. LPI (Lines Per Inch): The frequency of horizontal and vertical lines in a halftone screen.

Laser Printer:
A printer using laser copier technology to produce high-quality printed material from computer data. The laser charges an electrostatically sensitive drum to accept carbon based toners. The toner is then transferred and fused to paper or transparency material.

A LightJet printer uses Red, Green, & Blue Lasers to write a continuous tone image onto photographic printing paper in a similar manner to a film recorder. LightJets can produce high quality prints 48in. wide by however long.

Line Art:
Images comprised of only pure black-and-white data. Also a mode of capturing such images.

The number of halftone cells per inch expressed as lines per inch (lpi)

Loose Color:

Loose Color proofs are proofs of individual images that have not been assembled into page layouts. (see; Composite Color)

Lossless Compression:
Reduces the size of files by creating an internal shorthand that rebuilds the data as it originally were before the compression. Thus, it is said to be non-destructive to image data when used.

Lossy Compression:
A method of reducing image file size by throwing away unneeded data, causing a slight degradation of image quality. JPEG is a lossy compression method.


Lines Per Inch

Lempel-Ziv-Welch. A popular, lossless image compression algorithm.



A temporary stencil restricting the action of various functions to a selected area within the picture or page. Masks can be created by drawing points around an element or automatically by specific density or hue values.

A Matchprint is a printers Contract Proof made from the same halftone negative film that will be used to burn the actual offset printing plates. It is called a contract proof because the printer promises to be able to make the printed page match the Matchprint. Other, similar, contract proofing media are FujiPrint, PressMatch, and Cromalin Proofs.

Megabyte (MB):
An amount of computer memory consisting of about one million bytes. The actual value is 1,048,576 bytes.

Mega Pixel:
One Million Pixel image. Produced with higher end digital cameras.

The range of tones in an image located approximately halfway between highlights and shadows.

Multi-purpose Internet Mail Extensions. A standard for embedding multimedia data in e-mail messages.

Modem (MOdulator/DEModulator):
A device that converts digital computer data into signals for transmission over telephone lines.

A visible pattern that occurs when one or more halftone screens are misregistered in a color image.

A computer Display screen. A monitor is an RGB display device

An image compression method for motion picture files.



A group of computers connected to communicate with each other, sharing resources and peripherals.

An Internet discussion group devoted to a particular topic

Newton Rings:
A pattern of concentric, multi-colored rings occasionally introduced in a scanned image by contact of transparency film with the glass platen in a scanner.

Communications interface used in Macintosh computers to transfer video data from memory to the graphics display card.





Photoshop is the most popular Digital imaging software program. It allows for the color correction, tonal adjustment, sizing, and cropping of digital image files. It is also enables you to do retouching, image manipulation, compositing, and special effects.

The native bitmapped file format for Macintosh

A digital image is made up of small continuous tone spots called pixels. The word pixel is derived from the words Picture Element. In an RGB image (with a Bit Depth of 24) each pixel can be any one of 16.7 million colors/tones. Each pixel is made up of three color channels (Red, Green, & Blue) and each channel can be any one of 256 levels of tone (256 x 256 x 256 = 16,777,216)


The stair-stepped appearance of a curved line in digital imaging.


Windows Paintbrush bitmap image standard

An Offset Printing plate is a metal plate photo-etched from the halftone separation negatives.

A term taken from the motion picture industry which refers to all of the editing that takes place after the actual shooting of film.

To achieve the impression of continuous tone we need to reproduce 256 differentiations of tone from white to black. If we break down the tonal range into fewer differentiations you begin to see the breaks between the individual tones. We call this posterization, it often appears in smooth color gradients.


Postscript is a software printer description language used in typography, graphics and page layout programs that allows vector graphics to be rasterized (RIPíed) for output on a printer, imagesetter, or film recorder.

Pixels per Inch.

The process of preparing images, illustrations, and page layouts to be printed. Including scanning, separations, image manipulation, retouching, imagesetting, and proofing. (See: Post-Production)


An ICC description of a particular imaging input or output device that allows the Color Management Software to apply the proper color transformations to the image file to match the specific limitations of the device.





A two-dimensional array of black and white cells, called pixels or picture elements, which when displayed form an image or representation of an original document.

To convert vector graphic artwork into bit mapped artwork

A measurement of the amount of detail in an image file as measured in units per inch such as dpi, ppi, or lpi: Dots per inch, Pixels per inch, or lines per inch. Sometimes resolution is measured in units per millimeter. a ``Res 14" file would be scanned in at 14 pixels per millimeter which would be equivalent to 355.6 ppi (14 x 25.4 = 355.6)


Red, Green, Blue; the color language of computers. Computer monitors and digital cameras use these primary colors to create all of the colors seen on the monitor.

Raster Image Processing: to rasterize a file for output. When a page layout document such as a Quark file is RIP'ed all of the page elements (typography, photography, Illustrations, and Graphics) are assembled and rasterized into a Bit Mapped image to be output. It is in the RIP that the halftone screens are applied to the artwork.



Scanning Camera:
A digital camera that uses a single row of CCD sensing elements to scan the image one row of pixels at a time.

Output Simulation Mode is a feature color management software that allows you to accurately simulate on the monitor display what you will get on the printed page. This is accomplished by applying the profile of the specified output device and the monitor profile to the image file to appropriately limit the gamut and gamma of the displayed image. (see: Color Management)


A 35mm color transparency.

The process of using the computer monitor to accurately simulate what the image will look like when printed. Proofing on screen rather than with a hard-copy contract proof. Soft-proofing is only possible when using accurate color management systems and output simulation display modes.

Subtractive Color
A colorspace in which colored pigments are added to white paper. We start with White (paper) which is the presence of all colors and use Cyan, Magenta, Yellow pigments to subtract from the image to achieve black. The pigments subtract colors from the white light reflected off the paper. Yellow ink looks yellow because it absorbs (subtracts) everything except the yellow from the white light that is illuminating the page leaving on the reflected yellow light. (See: CMY and CMYK)



Tagged Image File Format is an industry standard raster file format, which consists of the image and header information.


Tones are changes in apparent brightness of a color. (see: Continuous Tone)


Trapping involves the addition of dots or pixels around the edges of an object so that you don't get white or colored gaps if the image is printed slightly out of register. This is necessary where two process colors meet but do not overlap. The trap causes a slight overlap


A standard of communication between scanners, imaging devices, digital cameras and the computer software. According to some, TWAIN is an acronym that stands for "Toolkit Without An Interesting Name". According to others, TWAIN is an acronym that stands for "Translator Without An Interesting Name". According to the TWAIN Working Group, TWAIN stands for TWAIN since they have never officially expanded its name to a long form.



Unsharp Masking:
This is a process where by the perceived sharpness of an image is enhanced by increasing the contrast along the edges where different tones meet.




Vector Graphics:
Vector Graphics use mathematical descriptions rather than rows of colored dots (Bit Mapped). Vector based graphics represent objects as geometric shapes; straight lines, arcs, etc. They can be scaled and rotated without a loss in quality. Vector graphics are used for illustrations and typography. Postscript is a vector graphic software language. Programs like Adobe Illustrator, Aldus Freehand, and CorelDraw are vector programs



Web Press:
An offset press that uses a continuous roll of paper rather than individual sheets (Sheet-fed). Web Offset is of lower quality then sheet-fed printing but is common where the press runs involve very large numbers of copies. Because the paper is a continuous roll and is moving very fast it is more difficult to achieve accurate registration.

The whitepoint of a color display monitor is the color temperature of the monitor. The color temperature is stated in degrees Kelvin (K) and represents how warm or cool the white of the monitor is. Uncalibrated monitors generally have a very blue white (often as high as 9300K) The printing industry uses a standard called D5000 which is 5000K and closely resembles Daylight.

computer running Windows on an Intel processor chip....your basic PC clone.


"What You See Is What You Get" refers to accurate screen images to print out.





A colorspace used in Photo-CD that is somewhat similar to LAB color in that it uses a Luminance channel to define the tones and details of the image. YCC also uses two chrominance channels to define the color of the image.



Home     Return to Education