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Digital Terms Glossary
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Glossary of Digital Photo Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Accelerator Board

A hardware expansion board specifically designed to accelerate or supplement the performance of a specific computer function such as CPU processing speed or input/output functions.

Access

To acquire data into a computer system, typically from a storage device or from an input device.

Access Time

The amount of time that is required to acquire a block of data from a storage device and read it into the computer system.

Active-Matrix Display

A type of flat panel LCD display used in laptop and portable computers. Active matrix displays produce a superior image to passive matrix displays.

Adaptive Compression

A type of compression software commonly used to back up files. The method of compression changes with the type of file, and is not recommended for photographic images because it may destroy original data.

ADC (Analog-to-Digital Converter)

The device responsible for converting an analog sample such as a voltage level to a binary quantity, or video tape to a digitized format.

Additive Colors

The three additive primary colors are red, green and blue. When these three colors of light are mixed in equal proportions they will produce white light. Also known as additive primaries.

Addressable Resolution

The maximum resolution of any device. The finite number of pixels that any imaging device is capable of creating, manipulating or imaging.

Adobe Acrobat

Adobe's software application for creation of Portable Document Format files that can display a document as it was originally designed without having the particular software or fonts used to create the file.

Airbrushing

A software tool found in many image editing programs that simulates the effect of a mechanical airbrush.

Aliasing

The visual stair-stepping of edges that occurs in an image when the resolution is too low. This can be caused by improper image sampling or improper image processing.

Algorithm

A mathematical routine that solves a problem or equation. In imaging, the term is usually used to describe the set of routines that make up a compression or color management program.

Alpha

The degree of opacity of an image in computer graphics. Not the same as luminance.

Alpha Channel

An additional eight-bit channel used by some image editing software applications for masking or additional image information. Many popular image editing programs use these channels for saving selections and masks.

Alpha Chip

A Digital Equipment Corporation produced RISC chip that is known for its processing speed.

Alpha Chip Analog

An electronic signal, tone or other measure that is continuously variable in its level.

Alternative Media

This refers to a large group of image output technologies on various substrata.

Anti-Aliasing

A technique used to smooth the transition between adjacent image areas. The removal or softening of jagged (aliased) edges by averaging or blending techniques.

AppleTalk

The local area networking system that was introduced by Apple Computer for use in the Macintosh environment.

Architecture

The particular basic design of a computer system. Refers to the basic components of the system, specific bus structure, and the standards, protocols, and instructions that define a specific microcomputer system.

Archival Storage

The storage of digital data in long-term, off-line storage devices.

Archive

Storage of selected digital files for backup or long-term storage.

Array Processor

A specific portion of a large computer system that assists processing data quickly. An array processor is sometimes capable of performing several operations simultaneously.

ARTA (Apple Real-Time Architecture)

The architecture of Macintosh 'AV' platforms that integrates audio and visual data.

Artifact

Unwanted visual anomalies or defects generated by an input or output device, or by a software operation, that degrade image quality.

Artificial Intelligence

The use of computers to solve problems and process information in ways that approximate human thought.

Ascender

The portion of a lower case type character which rises above the main body of the character, as in the upper half of the letter "b."

ASCII (American Standard Code for Information Interchange)

A coding system that converts font characters to standard numeric values.

Aspect Ratio

The relationship of an image's horizontal length and vertical height. The horizontal length number is placed first (i.e. 3:2).

Assembly

Combining numerous files to produce a finished product. Commonly used to describe the process of combining line work and continuous tone images into a final layout.

ATM (Asynchronous Transfer Mode)

A high-speed switching technique that enables the transmission of 155 Mbits (Mega bits) and 622 Mbits per second in packets.

ATM (Adobe Type Manager)

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

AV (Audio-Visual)

A generic term used to deal with animation, audio, video, and CD-I.

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B

Background Processing

Allows assignment of specific operations to the background while the computer continues to perform previously assigned instructions.

Banding

Contours or steps in a gradient produced by an inadequate range of brightness levels available to display the image. Banding can occur when displaying continuous tone images on a display using less than 24 bits of color information, or when printing a gradient that spans an extended distance without an adequate range of colors to create smooth transitions from shade to shade.

Bandwidth

The amount of data that can be transmitted. Also, video equipment specifications that indicate the maximum image resolution that will be possible with that equipment.

Barrel Distortion

Image distortion that spreads the center dimensions of the picture.

Base Resolution

The Photo CD image resolution (512 x 768 pixels) that is formatted for display on current consumer televisions.

4 Base

The 1536 x 1024 pixel image that is scanned and stored on a Photo CD. This image is ready to be used by High Definition Television Systems.

Base/4

An image resolution with 1/4 the number of pixels as Base Resolution.

Base/16

An image resolution with 1/16 the number of pixels as Base Resolution.

16 Base

The 2048 x 3072 pixels image that is scanned and stored on a Photo CD and suitable for digital imaging and desktop publishing applications.

64 Base

The maximum resolution image file that is available on Pro Photo CD disks. This 4000 x 6000 pixel file produces a 72 megabyte color image.

BASIC (BALUSTRADE Image Sensor)

A specific type of image capture sensor or CCD that can capture high quality digital images with a single chip.

Batch Processing

A method that allows for the repetetive processing of groups of data or several digital files by executing only one command.

Baud Rate

Used interchangeably with "Bits Per Second." The unit of measure used to rate the speed at which computer data can be translated via modem.Typical modem rates are 2,400, 9,600, 14,400, and 28,000 baud.

BBS (Bulletin Board System)

A system that allows computer to computer connection via modems to copy files or exchange messages.

Bernoulli

A removable hard disk system that is produced by Isomer Corp.

Beta Site

A business or location that is involved in testing a specific product just prior to release.

Beta Test

The testing of a software product in the field under real operating conditions prior to general release.

Bezier Curve

Curved line segments that are created by establishing endpoints and adjusting anchor points.

Binary

The numbering system used by most computers that uses only two digits, 0 and 1, to represent all numbers.

Bit

A Binary digit, this is the smallest piece of binary information used by a computer. A bit will have a value of either 0 or 1.

Bitmap Graphics

Graphics that are constructed of individual pixels.

Black

The fourth color in four-color printing. It is listed as the K in "CMYK." Black is required in the printing process because equal amounts of cyan, magenta and yellow inks will not produce a true black.

Black Generation

A term describing the addition of black ink to the other process colors when separating an RGB color image into CMYK colors. Black generation is typically handled in one of two ways, GCR or UCR.

Blanket

In offset printing, a rubber sheet which is wrapped around a cylinder on a printing press. The inked image on an exposed metal plate is pressed onto this blanket for transfer to the paper.

Bleed

Printing term referring to an image or inked area which extends to the edge of a printed piece. The bleed is the portion of the artwork that is beyond the trim marks of the piece. The bleed is required to account for any slight misalignment during trimming which would otherwise result in an unprinted strip of paper appearing at the edge of the finished piece.

Blend

In computer graphics software, the intermediate steps between two objects that are created when the objects are merged together via a specified number of intermediate transformations.

Blooming

A visual effect caused by exposing a CCD to too much light. This "digital overexposure" can cause distortions of the subject and/or color.

Blue

One of the three additive primary colors of light.

Blur

The softening of image detail. Blurring of an image is usually accomplished through software averaging of pixel values to soften edge detail.

BPl (Bits Per Inch)

A term defining the density of data in a bitmap image.

BPS (Bits Per Second)

A measurement of the speed of data transfer, used interchangeably with the term baud per second.

Brush

In many image editing programs, this is the term describing a special effects filter that performs a specific function, such smoothing selective edges. In some cases, the image editing programs present the brushes as an icon that actually looks like a brush.

Bubble Jet

A Canon ink jet printing technology that creates bubbles in the ink supply and propels the ink through small nozzles onto the print media.

Buffer

Part of the computer's memory used for temporary storage of information. This becomes necessary to compensate for differences in speed that different devices can transmit or receive data.

Browser

A software tool for accessing and navigating the World Wide Web.

Burn

In offset printing, the term for exposing a metal printing plate.

Bus

A data pathway used within a computer system to transfer information within the system.

Byte

A bundle of data containing eight bits. This is the common size unit for computer data.

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C

Cache

Temporary storage located between the hard disk and the computers RAM used to reduce the time needed for the computer to access data.

Calibration

A process of setting digital imaging components to standardized settings that will produce accurate and predictable results in the output.

Camera Ready

Artwork that is ready for photographic exposure to a printing plate.

Capture

Acquiring information, such as an image, with a scanner or digital camera device.

Cathode Ray Tube (CRT)

The tube used in televisions and computer monitors to display the output of the video signal or computer line information. CRT's use the additive primary colors red, green and blue.

CCD Array

An arrangement of CCD sensors mounted in close proximity that allows for the simultaneous capturing of many pixels with one exposure.

CCD Color Scanner

An input device that uses CCD's to sample an analog color image and convert the information into a digital form.

CCD (Charged Coupled Device)

A type of light detection device used in many popular scanners, digital cameras, and video cameras that generates electrical current in direct proportion to how much light strikes areas of the sensor.

CCITT (Consultative Committee for International Telephony and Telegraphy)

The CClTT has specified standards for communications throughout the world.

CD (Compact Disc)

A small plastic disc used to store digital information. A laser is used to read the digital information from the disc.

CD Interactive (CD-I)

A multimedia system that uses a CD-ROM XA disc that provides for simultaneous presentation of video, audio, data and text, allowing the user to interact by responding to prompts generated by software.

CD-ROM (CD-Read-Only Memory)

A compact disc format that allows storage of information in a read only format.

CD-R (CD-Recordable)

A CD format that allows the users to record data to a disc when using the proper hardware. Recorded data is not erasable.

CD-ROM-XA (CD-ROM Extended Architecture)

A specific type of compact disc-read only device that is compatible with the Photo CD format and other CD applications. Multiple session Photo CD's cannot be fully utilized on non-XA drives.

CEPS (Color Electronic Prepress)

A high-end digital publishing system specifically designed for color correction and image assembly.

CGA (Color Graphics Adapter)

A low resolution (200 x 300 pixels) color video standard for PC-compatible computers.

CGM (Computer Graphics Metafile)

A vector based standard for graphics files that allows images to be transferred between applications.

Chip

Common term for a computer integrated circuit.

Choke

In offset printing, a term describing a trapping relationship between a foreground element, and a background color or element. To create a trap between a foreground element that knocks out a background, the background may be "choked" or slightly encroach into the knockout created by the foreground element. See also "Spread" and "Trapping".

Chroma

The hue or color information associated with an image.

Chrominance

The portions of a signal that are dedicated to describing the hue and saturation. Used in measuring the difference between two colors of equal brightness.

CHRP (Common Hardware Reference Platform)

Computer platforms developed by IBM-Apple that share a common protocol allowing execution in many operating systems.

CIE (Commission International de l'Eclairange)

A set of color standards based on mathematical modeling of human vision and light. CIE color spaces are used for the communication of color independent of a specific device.

CLC (Color Laser Copier)

Canon's color laser output technology.

Client-Server

An efficient means of storing large files and applications on a server computer, rather than at the client computer or desktop workstation. A file server is generally used to manage files, an image server manages image files and so on. This is faster than having to move an entire file across a network.

Cloning

The process of producing an exact copy of existing digital image data, either to another image file or copying an area of an image within the same file.

Closed Architecture

Computer systems that are "closed architecture" severely limit the addition of peripheral devices to the system, especially devices from other manufacturers.

CLUT (Color Look-Up Tables)

A digital color processing technique that is employed when the display system is not capable of reproducing all of the colors available in the image. This presents the best possible combination of colors on the display for predicting accurate color for the output.

CMY (Cyan, Magenta, Yellow)

These three subtractive primary colors are used in color-negative printing and in some color output devices to produce a full gamut of color. The combination of pure CMY inks produces black, and the elimination of all three produces white.

CMYK (Cyan, Magenta, Yellow and Black)

The four colors of ink that are used in "four color process" printing to create the appearance of a photographic or full color. Black is added to compensate for the lack of purity in CMY inks.

Coated Paper Stock

A printing paper having a transparent, smooth layer added to one or both sides that changes the look of the final printing. Coatings are normally defined as hard glossy, semi-glossy or matte surfaces.

Color

Color is produced using a combination of luminance and chrominance signals.

Color Calibration

A system of software and/or hardware that matches the 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 that the next color device can use.

Color Correction

The process of adjusting an image to compensate for scanner deficiencies or output device characteristics.

Color Curve

A graphic mechanism for displaying color measurements and for making color changes to an image. User adjustments to the angle and slope of the curve implement color changes to one or all of an images color channels.

Color Key

A printer's proofing system developed by 3M that makes separate acetate sheets of CMYK that when stacked give a representation of the offset printing of a color image.

Color Management System (CMS)

A combination of software and or hardware devices used to produce accurate color results throughout a digital imaging system.

Color Model

Refers to the component colors used in the image, such as RGB or CMYK. This is also called a Color Space or Color System.

Color Proof

A color sample that attempts to represent the final printed image that will result when a piece is offset printed. Color proofs can be generated from film separations prior to using the separations to make printing plates.

Color Separation

The electronic or photographic process of separating a single RGB color image into the three subtractive primary colors CMY plus K (black) that will be used for reproduction. These four monochrome films are used to produce the plates in four color printing.

Color Space

A 3-D system used to describe a range of colors.

Color System

A concept that relates colors for description or reproduction. Models in imaging include CIE, PMS and Photo YCC among others.

Color Temperature

A scale used to refer to the visible energy system of various light sources. The scale uses degrees Kelvin as a measure of the mixture on a scale from red to blue white. Daylight = 5500 Kelvin, a blue-white color. The Tungsten in a light bulb produces about 3200 Kelvin, an orange color.

Colorimeter

A device for measuring color values.

ColorSense

A color management system developed by Kodak to deliver predictable color control even when using multiple computer platforms and software applications.

Colorsync II

A color management software developed by Apple computer. ColorSync manages the color between digital devices by comparing each device's color description to the standard CIE color mode.

Comp

An abbreviation for composite or comprehensive. A layout that is produced during the design process providing a preview of the finished print job.

Compact Disc Erasable

A type of compact disc that allows for the disc to be recorded, erased and re-recorded.

Composite Video

A video signal that includes the luminance and chrominance signals, along with the burst signal and sync signals. Composite video signals are transmitted over a single wire. The standard television signal.

Compression

The process of reducing the size of a data file, usually accomplished through software processing. This is used to reduce the required storage space or cut transmission times.

Computer Program

Term used to describe a specific piece of software for a computer system. Sometimes referred to as an application.

Computer-to-Plate

A method of applying an image onto an offset printing plate. The image is transferred from a computer directly to the device that exposes the image onto the plate, bypassing the need for separations and film.

Console

Terminology sometimes used to describe a computer monitor and keyboard.

Contact Print

A photographic print made from a negative or positive original in contact with a photographically sensitive film, paper, or printing plate.

Continuous Tone (CT)

An image that consists of a visually infinite tonal range of colors or gray values. Value changes appear as a continuous gradient.

Contouring

See "Banding."

Contrast

The measure of difference between the lightest and darkest values appearing in an image. High-contrast images contain mainly dark values and white values with few steps or tones available in the image.

Copy

The text character elements of a page layout; or to duplicate digital data from one location to another.

Copyright

The legal ownership of artistic or written material. Assignment of the copyright can be transferred by contract.

CPU (Central Processing Unit)

The main processing portion of a computer. This section contains processing and control circuitry along with internal storage areas.

Cropping

The process of cutting away unwanted portions of an image. For instance, an image may be cut down to only include a person's face.

CT Merge

The process of combining two continuous tone image tiles to create a seamless blending of the two images.

Cyan

One of the three subtractive primary colors. Produced by mixing equal amounts of blue and green projected light. Cyan is also one of the four colors used in 4-color printing.

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D

D-RAM (Dynamic Random Access Memory)

The term describes memory within the computer that is constantly changing.

DAC (Digital-to-Analog Converter)

Any device capable of converting discrete digital binary numbers into continuous analog signals or voltages.

DAT (Digital Audio Tape)

A recording format that is commonly used for data storage and data backup because of its low cost per megabyte.

Data

The numbers that make up a digital file.

Data Base

An organized collection of data or information.

Data Compression

The process of reducing the size of a data file, usually accomplished through software processing.

Datum

The singular of data.

DCS (Desktop Color Separation)

A Computer file format that includes four EPS files for CMYK and a PICT file for screen display.

DDCP (Direct Digital Color Proof)

A color proof that is produced directly from the digital file without creating color separations.

DDES (Digital Data Exchange Standard)

A set of standards developed by suppliers and end users of digital image processing hardware and software to ensure that data could be exchanged between digital prepress equipment without the need for conversion.

Densitometer

A device used to measure the density of light transmitted or reflected by paper or film. It is used to check the accuracy, quality and consistency of an output device.

Density

The degree of opacity of a photographic film.

Descender

The portion of a lower case type character which falls below the main body of the character, as in the lower half of the letter "p".

Descreening

A feature of some scanners that allow them to eliminate moire patterns that can occur.

Desktop Publishing

The use of desktop computers to create and perform some prepress operations for printing and publishing.

Device-Independent Color (DIC)

Any color matching system that is based on a device independent color model, such as ClE, rather than being based on the color gamut of one particular piece of equipment.

DIF (Data Interchange Format)

A standardized format that allows for the exchanging of digital data between different programs.

Digit

A single unit from which all data is built.

Digital

Information or data that exists as numerical values (1 or 0) based on a binary coding system.

Digital Camera

A filmless camera system. Any camera system that is capable of converting an analog image info a digital signal or file.

Digital Duplicates

Reproductions of an image that are produced by scanning the original analog image to produce a digital image file, and then imaging the digital file using some variety of digital printing or recording device.

Digital Halftone

The use of fine pixels to create the halftone pattern that is then written to film, direct-to-plate or direct-to-press for printing.

Digital Internegatives

Internegs that are produced by digitally scanning the original transparency to create a digital file, and then imaging the digital data using a film recorder to record the image onto a negative film stock.

Digital Printer

Any printing device that is capable of translating digital data into hardcopy output.

Digital Signal Processors (DSP)

Microprocessor chips specially designed to convert, modify and manipulate streams of digitized signals in real time. These chips allow for faster telephony, faxing, and audio and video capture and editing.

Digitize

The process of sampling analog data and converting (quantizing) the signal into a digital data format usable by a computer.

Digitizer

A device that allows the user to plot position points on a tablet using a mouse or stylus in order to input drawing coordinates into a computer system.

DIMM (Dual Inline Memory Module)

Used to add additional RAM memory to computers.

DIP (Dual In-line Package as in DIP Switches)

Small switches used on some computer peripherals in order to change operating settings.

Direct Digital Color Proof

Using any of a number of output devices to create a proof from the digital file rather than by a photo-mechanical method.

Direct Memory Access

The ability to use memory without a software interface.

Direct-to-Press Printing

Printing devices that allow for the elimination of film separations from the printing process. These systems utilize a computer controlled system employing lasers to "write" digital data to a plate that is already mounted on the press.

Disc

The spelling variation of "disk" referring to compact discs such as Photo CD or other CD-ROM.

Disk Drive

A device that can contain a fixed or removable spinning disk used for storage of digital data.

Dithering

A process used by some output devices to simulate shades of gray or color variations with a randomizing technique that uses varying sizes and shapes of pixel groupings instead of an ordered array of halftone dotes.

DOS (Disk Operating System)

The main system software that tells your computer how to work.

Dot

Dots make up an image in color separations or halftones. Halftone dots will have a fixed density but have variable size (amplitude modulation).

Dot Gain

The effect produced by the expansion of individual dots in a halftone screen when printed onto paper. Dot gain results in a darkening of a printed image and is influenced by the tendency of different papers to absorb ink.

Dot Matrix

An impact printing process that uses a series of dots to create all images, lines and text.

Dot Pitch

The distance between the dots on a computer monitor, typically 0.2 to 0.3 millimeters. The closer the dots the sharper the image on the monitor.

Download

The process of receiving data from another computer, server or system.

DPI (Dots Per Inch)

The unit of measure used to describe the resolution of image files, scanners, or output devices. The measure of distinct pixels that a device can produce either horizontally or vertically in one inch.

Drag and Drop

Terminology used to describe an option in graphical user interfaces where tasks can be accomplished by simply dragging an icon to a specified area.

Draw Program

A software program that can create and manipulate object oriented graphics.

Drive Speed

The speed (RPM) that a drive mechanism rotates. Faster drive speeds allow for faster data transfers.

Driver

A small software program used to interface with and control a peripheral device such as a scanner or printer.

Drum Scanner

A type of optical scanner where the reflective or transmissive art is mounted to a rotating drum. As the drum spins, light from the image enters a lens allowing the image to be recorded in a series of fine lines.

Dry Silver Color Process

A printing technology developed by 3M that constructs the image on a receiver material without the use of developing solution.

DSP (Digital Signal Processor)

Chips that are designed to facilitate digital video and audio, along with accelerating image processing.

Duotone

A monochromatic printed image created by two overlapping halftone screens of different colors; generally created from a black and white photographic original in order to add additional tonal range, or to create a tinted or colored appearance.

DVD (Digital Versatile Disc)

A technology similar to Compact Disc, but far superior in its storage capacity. A DVD can contain about 4.7 GB of data in its single-sided, single-density version, and 18 GB or more in a double-sided, double-density version, or about 40 times more than a CD.

DVI (Digital Video Interactive)

A technology that allows for interactive video by the compression of approximately 70 minutes of video on one standard CD-ROM.

Dye Sublimation (Diffusion Transfer)

A color printing technology that forms the image by delivering gaseous dyes to the receiver material with a thermal driver. This creates near photographic quality images.

Dynamic Range

The measurable difference between the brightest highlight and the darkest value that any system can scan, create, manipulate or write. The range of gray values that a system can reproduce.

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E

EGA (Extended Graphics Adapter)

A medium resolution (640 x 350) color display standard in PC compatible computers.

EISA Bus

A type of 32 bit data bus used in PC's.

Electroinks

These are used in direct-to-press printing applications. They work in a manner similar to a laser copier's toners.

Electronic Dot Generation (EDG)

The process used in digital halftone production that allows negatives or plates to be generated by grouping micro dots into regular groups to function in the same manner as a photographically produced halftone.

Electrophotographic Copier

A printing technology that electronically changes an image area on a metal drum. Toners adhere to the changed area and are transferred onto paper.

Electrostatic Plotters

A color output technology that is capable of producing large, simulated continuous tone prints using CMYK toners applied using a plotter-type printer.

Emulsion Side

The side of photographic film or paper coated with the silver emulsion. Film output is specified as emulsion up, or emulsion down.

Encapsulated PostScript (EPS)

A file format developed by Adobe that stores graphics and text as Postscript language commands that a printer can read and print. These files contain low resolution preview files in addition to the high resolution Postscript commands.

Encryption

The process of scrambling a signal or digital file so that de-scrambling hardware or software is needed for a receiver to use the image.

Equalization

An image processing technique where the range of tones or colors in an image file are expanded in order to produce a more pleasing image.

Error Diffusion

A screening technology used in digital continuous tone printers where fixed-sized dots are placed based on image detail and tone values to enhance sharpness and detail while avoiding posterization problems.

Ethernet

The networking system originally developed by Xerox that allows for data transfer between computers and peripherals of up to 10 megabytes per second using coaxial cable.

Extended Architecture

A type of CD-ROM drive that allows for the use of multisession discs, such as Photo CD.

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F

Feathering

A technique in many image editing programs that allows for the softening of the edge around a selection.

Fiber Optic Cables

Cables made of very thin glass fibers that use light pulses to transmit data instead of electricity. These cables have greater bandwidth than electrical transmission through wires.

Field Image

An image that is half of a complete video image (frame). NTSC video contains 525 horizontal lines. A field image is 262.5 lines that represent a set of either the odd or even lines of an interlaced video image.

File Converters

Hardware or software that is used to convert files from one type of file format to another format.

File Format

The particular arrangement of digital information that is saved from an application program. The method of arrangement or storage is unique for any particular application program, but most applications can import and export standardized graphic and text file formats, such as TIFF, GIF, and EPS graphuics; or RTF or ASCII text.

Film Recorders (CRT& Drum)

A device used to output digital files onto film materials. CRT film recorders use a cathode ray tube and RGB filters to create the film image. Drum-based film recorders/writers include sheet-fed and roll-fed models and use white light or lasers to record the image on film.

Filters

Software that is used to modify digital images by altering the values or arrangement of selected image pixels.

Firmware

Software that is embedded into a computer's ROM chips. This information is permanently burned into the chip and cannot be changed.

FITS (Functional Interpolating Transformational System)

A software technology that allows the user to edit very large image files in near real-time by accessing only the image data being edited.

Fixed Disk

Another term used to describe a hard disk drive. A hard drive that cannot be removed is a fixed drive.

Flash Memory

A special type of RAM memory that stores data without electrical current. This type of memory is currently used in a number of digital cameras and some portable computers through the use of credit-card sized devices.

FlashPix

An image file format developed and supported by Eastman Kodak Co., Microsoft Corp., Hewlett-Packard, Live Picture and other companies. The format uses FITS (see FITS) technology to facilitate the transmission and manipulation of large image files.

Flat

In offset printing, a paper or film holding all of the photographic films required to make a particular printing plate.

Flatbed Scanner

A scanner which utilizes CCD linear arrays, where the image is placed on a glass platen, and the CCD array moves past the artwork.

Flexible Disk - See Floppy Disk.

Flicker

A perceivable fluctuation of the brightness levels of a displayed image. This problem is often present in CRT monitors that have a vertical scan rate that is lower than 50 Hz.

Floppy Disk

A magnetically coated removable disk used for the storage of computer information. Floppy disks come in two common sizes, 5-1/4 and 3-1/2 inches, and store from 360K to 2.88 MB.

Floptical

A floppy disk storage device that uses a light beam to accurately position the magnetic head and is capable of storing 21 MB.

Font

All of the numbers, symbols, and letters in a single typeface.

FPO (For Positioning Only)

A term used for low resolution images used in layouts to define the position of images. The FPO is replaced in the final production process with the original (high resolution) image file.

Fractal

A mathematically generated pattern that is reproducible at any magnification or reduction.

Fractal Compression

A type of video compression that utilizes fractal-based compression algorithms.

Fractal Image

An image that is created by mathematically generated geometric shapes containing an infinite amount of image detail.

Frame Buffer

An area in RAM memory set aside to specifically hold the data for the screen display.

Frame Grabber

A computer expansion board that is capable of digitizing and processing video signals, converting the video signal to a single digital image that can be read and displayed by a computer.

Frame Image

A video image that is the combination of two fields and includes the odd and evenly scanned lines. One frame represents 1/30 of a second of video viewing time.

FTP (File Transfer Protocol)

The language used to facilitate the transfer of files from a server on the internet to another location, such as a desktop computer or another server.

Full Bleed

Printing term used when an image or background extends to the final trim edge of a printed page.

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G

Gamma

Refers to the slope of the line that represents image output values versus the image input values. The term gamma is also sometimes used to describe the contrast of a monitor.

Gamma Correction

The nonlinear tonal correction editing an images 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 that are available in an image or output process.

Gamut Compression

The editing of an image to reduce the color gamut so that the image can be displayed or output within the limits of a particular device.

Gamut Mapping

The plotting of an image color gamut into the CIE color space.

Ganging

Putting a group of images or jobs on the scanner or press at one time.

Gateway

A computer server that allows for the connection of different computer networks using protocol conversions.

Gaussian Blur

An image softening effect utilizing a bell shaped gaussian distribution to apply the softening effect.

Generation Loss

The loss of quality that is unavoidable in any type of analog duplication such as an interneg. Digital images do not suffer this loss of quality when duplicated.

Ghosting

The effect of changing an object's level of opacity.

GIF (Graphics Interchange Format)

A graphics file format common to online services and the Internet. A GIF utilizes a 1 to 8-bit palette to minimize file size (pronounced "jiff").

Gigabyte (GB)

Approximately one billion bytes (1000 Megabytes). The exact number is 1,073,741,824 bytes.

GPIB (General Purpose Interface Bus)

A standard interface bus popular on PC compatible computers for connecting peripheral devices.

Gradation

A smooth graduated transition between two colors or between black and white. Also known as a gradient.

Graphics Accelerator

A computer expansion board that is specifically designed to increase the performance of graphics software tasks.

Graphics Tablet

A device that allows the user to plot position points on a tablet using a mouse or stylus to input drawing coordinates.

GCR (Gray Component Replacement)

A type of process color separation which determines the amount of black ink used to replace Cyan, Magenta, and Yellow in areas where those three inks overlap.

Gray Scale (or Grayscale)

An image containing a range of gray levels as opposed to only pure black and pure white.

Green

One of the three additive primary colors of light (Red, Green and Blue).

GUI (Graphical User Interface)

A computer interface or control system that uses graphical icons to control the computer operations. The Apple Macintosh interface and Microsoft Windows are examples of graphical user interfaces.

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H

Halftone

The process of reproducing a continuous tone image as a series of various sized dots within a fixed grid that can be reproduced with ink on a printing press. The finer the dot grid the higher the quality of the reproduction.

Handshaking

This is a method that allows computers or communications equipment to coordinate transmissions. This is particularly important in higher speed communications.

Hard Copy

Any kind of printed or proofing output, as opposed to display on a monitor.

Hard Disk or Hard Drive

A computer storage device that contains a fixed magnetically coated disk used for storage of digital data.

HDCP (High Definition Color Printing)

A specialized color printing process that uses balanced dot frequency and screen rulings as fine as 625 lpi to reproduce near-photographic quality images.

HDTV (High-Definition Television)

A television system that incorporates 1000 or more horizontal lines of resolution (twice current standards) along with a wider aspect ratio and digital quality audio.

Hertz (Hz.)

A scale used for measuring the number of cycles per second.

Hi-Fi Color

An alternative printing process that extends the capabilities of printing presses. This system uses stochastic screening, 6-color printing, and other techniques to expand the possible color gamut well beyond that of traditional 4-color processes.

Highlight

The brightest/lightest area within an image.

Histogram

A graphical display which represents the distribution of tones within an image. The horizontal coordinate represents each pixel value possible from black to white. The vertical values indicate the number of pixels in the image that occur at each value level.

HLS (Hue, Luminance, and Saturation)

A color model that utilizes Hue, Luminance, and Saturation as the three coordinates.

Holography

A photographic system that uses laser light to expose film to a pattern developed by the interference pattern of the laser and the reflection. When these films are viewed under specific conditions a 3-D image is visible.

Home Page

The main page of a web site. Navigation of a web site begins from this home page. Most home pages include links to other pages of the web site.

Horizontal Resolution

The number of vertical lines that a system is capable of producing (counted on a horizontal axis).

Host

Usually referring to a computer server that can be accessed over a network

HSB (Hue, Saturation, and Brightness)

A color model that utilizes Hue, Saturation, and Brightness as the three coordinates.

HSV (Hue, Saturation, and Value)

A color model that utilizes Hue, Saturation, and Value as the three coordinates.

HTML (Hypertext Markup Language)

A computer language and format that describes the components of graphics and text material presented on the World Wide Web in a consistent manner.

HTTP (Hypertext Transfer Protocol)

The method that is used to retrieve HTML documents on the World Wide Web. This takes place transparent to the user once the URL (Uniform Resource Locator) address is accessed. (For example, PMA is located at http://www.pmai.org)

Hue

One of the components of color. The hue can be specified by the particular wavelengths or by CIE coordinates.

Hybrid Imaging

Electronic imaging systems that mix traditional silver-halide technologies with digital imaging technologies.

Hyper-Compression

A technology developed by Eastman Kodak Co. that compresses a photographic image by several hundred times, reducing the image to just a few bytes of information. It allows an entire image to be stored in a portion of a barcode or on the magnetic strip of a credit card. When decompressed and viewed on the monitor, it produces a low resolution, but recognizable, black-and-white-image.

Hypertext

A document made up from several blocks of text that are linked within the computer. This process is used in networks such as the internet or LAN's.

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I

I/0 (Input/Output)

Used to refer to the portions of a computer that handle the movement of digital data from storage devices such as hard drives into RAM or other storage devices.

IC (Integrated Circuit)

The use of transistors created in silicon chips that are used for the various parts of a computer's circuitry.

Icon

A small graphic or pictorial image on the screen used to represent digital files or applications, and accessed using a mouse or tablet.

IHS (Intensity, Hue, and Saturation)

A color model where colors are expressed by three values representing Intensity, Hue, and Saturation.

Image Processing Board

A hardware expansion board specifically designed to enable or accelerate the performance of specific image processing programs or functions.

Imagesetter

A high resolution laser output device that is used to record bitmapped data onto film or photographic paper. These devices are available in flatbed and drum models that image at resolutions of 1000 dots per inch or more.

Import

To access a separate file while working on a document within an application program for use in that current document.

Imposition

The process of positioning pages of a publication into the correct position so that after the job is printed and folded, the page order will be correct.

Initialize

A preparation stage that equipment and storage media must go through in order to be ready for a task. The initialization process clears equipment or media of any old data or instructions.

Ink Jet

A nonimpact printing technology where ink droplets are propelled at the paper to form characters or graphics.

Input

Any type of information that is fed into a computer system for processing or storage. Input could come from digital cameras, scanners, storage devices, keyboards, mice, or a number of other devices.

Interactive

A system where the operators' input and the application's actions are inter-related. Interactive programs often permit or require the operator to respond to prompts in order to move forward in the program.

Interface

The connection between operator and the system. A keyboard, mouse and monitor can all be considered to be interfaces between operator and system.

Interlaced, Interlacing

The standard technology applied to video monitors and television where the odd field is scanned by the electron guns (every other line) followed by the scanning of the even lines. This technology is employed in television monitors to reduce noticeable flickering but interlacing in computer monitors can cause flickering. The best computer monitors are non-interlaced.

Internal Data Path

The programmed path that data travels in any given application.

Interpolation

A sampling technique used to increase the size of an image file by creating more pixels and increasing the apparent resolution of an image. Interpolation examines the existing pixel information and creates additional pixels by averaging the existing values.

IPU (Internal Processing Unit)

The main processing unit that controls the speed and the operation of a computer.

ISA Bus (Industry Standard Architecture)

A 16-bit bus for PC compatible computers that was first introduced in the IBM AT.

ISDN (Integrated Services Digital Network)

An international standard for telecommunications that allows for data, video, and voice transmission over the same phone lines.

ISO 9660

The standard for CD-ROM that covers physical characteristics, such as the width of tracks, and the logical parameters such as methods for naming files and extensions. The standards are set by the International Standards Organization.

IT8

The lT8 committee developed the standards for the exchanging of digital data in graphic communications programs and prepress production systems. Also known as Digital Data Exchange Standard.

IVUE

The file format invented by Live Picture. This file format uses FITS Technology to allow for near real-time access to the entire image or selected segments and unlimited image zooming.

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J

Jaggies

The visual stair-stepping edges, known as aliasing, that occur in an image when the image resolution is too low.

Java

A computer language announced by Sun MicroSystems in 1995 that allows desktop computers on a network to access only the portion (called an Applet) of an application they will need. The application itself resides on a networked server, eliminating the need for a software application to be registered and paid for every user. It also enhances websites on the internet by making it easier to integrate video into a homepage.

Jazz Drive

A storage device manufactured by Iomega that allows for up to one gigabyte of information on a single low cost storage media.

JPEG (Joint Photographic Experts Group)

A graphics file format designed for use with photographs and other color bitmaps. The JPEG format uses compression algorithms and an "averaging" technique to create files that are smaller than would be the case with other graphics file formats. Saving an image as a JPEG files does cause a very minor loss of image data and in some cases, quality.

Jukebox

A device providing access to a large number of CD-ROM's by mechanically finding, retrieving and playing each disk.

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K

K (Kilobyte)

1,024 bytes of computer memory.

Kan Image

A camera system using a vibration technique to move the CCD to provide higher resolution images.

Kelvin

A temperature measuring scale used to describe the color of light. The lower the color temperature the redder the light, and the higher the color temperature the bluer the light.

KEPS

Eastman Kodak's system to bring Photo CD to the prepress industry using the Kodak Precision Color Management System.

Kerning

The fine adjustment of the spacing between pairs of type characters in a word to create visually pleasing and consistent spacing.

Knockout

In offset printing, when a foreground object lays over a background color or object, the foreground object is said to knockout the background if it replaces the ink that would otherwise have appeared in the area underlying the foreground object.

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L

LAN (Local Area Network)

Formed by interconnected computers within a single work site.

Landscape, Landscape Mode

The orientation of an image that is wider than it is tall; a setting controlling an output device to properly fit a computer document to the print medium.

Laser Scanner

A scanning device using a laser light source to record the image.

Lasso

A tool found in many image editing applications allowing the operator to select an area by drawing around it.

Leading

In typesetting, the vertical distance between lines of type; usually measured in points (pronounced Led-ing).

Library

A storage system organized to retain and give access to files, data, images, programs, etc.

Lightness

A concept often referred to as brightness that refers to the amount of perceived light reflecting or emanating from a subject; also refereed to as Luminance.

Line Art

Artwork that is only black and white, with no other tones included.

Line Screen

A term referring to the organization of elements of a halftone printing screen. Normally used to define the density of the screen; i.e. a 133 Line Screen refers to a pattern with 133 halftone dots/inch. A higher or "finer" line screen will create a sharper, more detailed image.

Linear Scanner

A scanning device that uses a linear array CCD. The linear array "sees" one line of the image at a time, and the linear array is moved past the image or the image is moved past the linear array in steps in order to capture the entire image area

Linearization

A process that calibrates the input and the output of tonal slope (gamma) to be equalized.

Local Bus

Part of the architecture of computers that form pathways for the transmission of data. These are fast pathways for moving data to RAM.

Lossless Compression

Any compression technique wherein no loss in image data will occur when the image is compressed.

Lossy Compression

Any compression technique wherein some loss of image data will occur when the image is compressed.

LPl (Lines Per Inch)

See "Line Screen"

LPM (Line Pairs per Millimeter)

The pixel density of a digital image measured in millimeters.

Luminance

The lightness or brightness of an image. A concept and control in some software that changes or imports only the color lightness information within an image.

LUT (Look-Up Table)

Information tables that allow an operator or software to use data relating to conversion functions for a particular device; i.e., there are film LUT's for each output device that correct the machines color balance to match the film's recording characteristics.

LZW (Lempel-Ziv-Welch)

A lossless compression technique common to TIFF files that allows smaller storage sizes.

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M

Macro

A predetermined pattern of key strokes that are activated to save time when doing a repetitive task on the computer.

Magenta

A subtractive primary color for printing. It is made up of equal parts of red and blue projected light.

Magnetic Disk

A storage medium used to record electronic data by magnetically imprinting on the disk.

Makeready

The steps required to set up a print run on an offset printing press; also used to describe the first printed pieces produced by the press while proper press settings are in the process of being established.

Marquee

A selection tool in image editing programs typically represented by animated dotted lines that surround a selected area of an image.

Masking

A technique that allows manipulation of one area of an image while other areas remain unaffected.

Mass Storage

High volume storage or archiving systems.

Match Print

A direct digital color proofing process developed by 3M that allows the printer to see the colors desired in the final printing.

MCA (Micro Channel Architecture)

The design of computers that allows expansion through plug-in modules.

Mechanical

Camera-ready-art prepared by conventional means that is ready to be made into halftone negatives or plates.

Megabyte (MB)

1,048,576 million bytes of computer memory.

Merging

Putting two or more data files together. Typically used to describe the merging of two channels of a bitmap image.

Metafile

Files that can be shared by more than one application program.

Metamerism

Two colors that appear the same under certain light conditions while differing under other light conditions.

MHz (Megahertz)

A unit of measure for frequency that relates to the processing speed of a computer. Equal to one million hertz.

Microprocessor

A combination of transistors designed to perform specific tasks. These transistors are designed into silicon chips to form the central processing unit of a computer.

Mini Discs

A small (3 inch) CD developed by Sony.

Mirror

A software function that vertically or horizontally reverses an image.

Mixers

A device that puts together multiple inputs.

MO Disks (Magneto-Optical)

These use a combination of magnetic and optical technology to allow for erasable optical storage disks.

Modem

A device that allows a computer to communicate via phone lines to other communication devices or networks.

Moire

An undesirable pattern effect that occasionally appears in combinations of overlapping halftone screens. Changes to screen angles will often eliminate moire patterns.

Moire Pattern

A visual defect that occurs in half-tone printing when the dots of the different separations used to create the half-tone image are at the wrong angles (See Screen Angles).

Monitor Calibration

The process used to bring a monitor's specifications of color, saturation and brightness into synchronization with the final output device, allowing the user to assume that what is seen on the screen will be extremely close to the final output in appearance.

Morphing

Moving smoothly from one image to another by having the computer animate a sequence transposing points in the starting image to corresponding points in the final image.

Motherboard

The major circuit board of a computer that contains processors, acts as a host to the peripherals, and operates software.

Mouse

A device that when moved across a surface makes a corresponding motion of the cursor on the computer screen.

MPEG (Motion Pictures Expert Group)

A motion picture compression system.

MS-DOS (Microsoft Disk Operating System)

A major command-line based operating system for PC's.

Multimedia

A term that is commonly used to mean a computer presentation incorporating a combination of graphics, audio, video, and interactivity.

Multiplexing

A single processing channel that simultaneously allows many tasks or outputs.

Multiscan

A trademark of NEC for a multiscanning monitor.

Multisession

A designation that means that data can be written to a Photo CD on more than one occasion.

Multitasking

When a computer can work on more than one task or program simultaneously.

Multithreading

Similar to multitasking, this is a chip technology that routes information through more than one channel in bursts of information, followed by bursts of information from another task. The two tasks share time on the chip, giving the appearance of multitasking.

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N

Nanometer

Visible part of the electromagnetic spectrum ranges from 400-700 NM.

Nanoseconds

A time measurement equal to one-billionth of a second.

Native Files

The original computer files, in their original application forms, for a digital graphic or publication; as opposed to an export format, Postscript print to disk format, or other transformed format which can no longer be opened and edited by the original programs used to create the graphic or publication.

Negative

Film containing a reversal of an image, such that the values of the original are reversed with light becoming dark, and vice versa.

Network

Interconnecting several computers or communication devices.

Newton Rings

Concentric multicolored rings caused by the pressing of film to glass. This can be a problem in scanning from negatives or transparencies.

Noise

In image editing applications, a random pattern of unwanted pixels or pixel groupings called artifacts.

Non-Impact Printer

A printing process that transfers the ink to the paper without pressure.

Non-Interlaced

Refreshing the monitor screen without using a method that scans odd lines followed by the scanning of the even lines. This technology is employed in television monitors to reduce noticeable flickering, but interlacing in computer monitors can cause flickering. The best computer monitors are non-interlaced.

NTSC (National Television Standards Committee)

NTSC is the standard television and video signal configuration used in the United States, Canada, Japan, Central America and much of South America.

NuBus

A hardware interface in Macintosh computers that allows the connection of various peripherals or specialized circuit boards to the computer. Most Macs now use a PCI bus (See PCI).

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O

OCR (Optical Character Recognition)

Software that allows the computer to convert documents that have been scanned and saved in a graphics format back into editable text.

ODC (On-Demand Color)

This term typically refers to short run color printing. These processes include ink-jet, electrostatic and direct-to-press.

Off-Line Storage

Storage system that is not resident within the computer and can be removed; i.e., floppy disks, Syquest disks, etc.

Offset Printing (Offset Lithography)

A common printing process that makes prints by transferring ink to a rotating "blanket" that contacts the paper.

OLE (Object Linking and Embedding)

Built into Windows 3.1 and later versions, including Windows 95. It allows a data file (such as an image or video and audio clips) to be either linked to another file in an application that supports OLE, or the data file can actually be embedded in the application file. If a linked data file is altered, it will automatically be altered in the application file as well. If a data file is embedded in the application file, it is protected from alteration by others.

On-Line

A term in relation to private networks, such as CompuServe, AOL, the Internet or World Wide Web that refers to being connected or actively participating in various aspects of these computer communication networks. For instance, on could access PMA on CompuServe (Go:PMAI) or the World Wide Web (http://www.pmai.org).

On-Line Storage

Storage systems or media device that is connected to the CPU.

Open Architecture

The design of a computer that allows additional non-proprietary hardware or software to be used without factory installation.

Operating System

The system used by the computer to control basic operation and software applications.

OPI (Open Prepress Interface)

A page layout system where original photographic images are scanned by the prepress service and low resolution files of each image are supplied to the page layout designers. The system later replaces the low resolution for-placement-only images with high resolution image scans before the final film separations or printing.

Optical Disk

A digital disk storage system commonly used for mass storage.

Optical Resolution

The maximum physical resolution of a device. Optical resolution provides better quality than interpolated resolution which uses software to create additional image information.

Optical Scanner

A device that changes images from either reflection or transparency medium to digital data.

Optical Storage

A storage device that is designed to store large amounts of data, CD and "flopticals" the prime examples of this system.

Orientation (See Landscape and Portrait)

The direction that the page is printed; horizontal = landscape, vertical = portrait.

Overprinting

Printing one ink or tint build over another, most commonly for trapping purposes.

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P

Page Layout

The process and software that prepares artwork into the page form to be printed.

Pagination

Putting pages of a publication into order.

Paint Program

A software program that can create and edit bit mapped images.

PAL (Phase Alternation Line)

A standard for video that is common in Western Europe, Australia and other countries.

Palette

The range of color or tone available in the imaging process, or a movable menu of tools or options found in software applications.

Pantone

A company producing numerous color matching systems for print and computer applications. The PMS color matching system is commonly used to represent 3000 distinct colors through a numbering system.

Pantone Matching System (PMS)

A printing industry-standard set of color inks.

Parallel Port

This is a channel for 8 bit data transmission in or out of the computer.

Parallel Processing

When an array of processors or segments of the CPU work at the same time to speed processing or multi-task.

Passive-Matrix Display - See Active-Matrix Display

Paste-Up

A traditional method of preparing artwork where elements are attached to backing by glue, cement or wax.

PCI (Peripheral Component Interface) Bus

A 32-bit pathway used to connect peripherals or specialized circuit boards to the CPU.

PCMCIA Memory Cards (Personal Computer Memory Card Information Association)

A storage memory device the shape of a thick credit card

PCX (Paintbrush Extension)

A bitmap graphic format for images common to many PC's.

PDF (Portable Document Format)

An electronic document format that allows the distribution of digital files across any platform that can display a document as originally designed and formatted without having the software application or fonts on the viewing computer. A reader, such as Adobe Acrobat Reader software, for viewing PDF documents is free and available on many websites, including http://www.pmai.org.

PDL (Page Description Language)

A specific set of commands and instructions that allow page information to be printed to an output device that uses that same language.

Pentium

A CISC microprocessor chip manufactured by Intel available in IBM type computers.

Peripheral

Any of a number of hardware devices that extend or enhance the performance of the computer and are not part of the CPU, though some are mounted inside the case of the computer.

Persistence

The effect of having an image on a computer monitor remain even after refreshing.

Phase Change Printer

A printer that stores its ink in a solid form that is liquefied to allow the ink to be deposited on the receiver.

Phosphor

The chemical substance on the inside face of a computer screen that illuminates when electrically charged. The color accuracy and luminance values of phosphors change over time, necessitating regular monitor calibration if consistent color is required.

Photo CD

A trademarked Eastman Kodak designed storage system for photographic images using a CD as media.

Photo Composing

Typically, this term is used to describe the process of combining all or part of more than one image into one image, possibly with text.

Photo YCC

A color standard established by Eastman Kodak that is used to define the color space for digital imaging in Photo CD and desktop publishing.

Photothermography

A process that uses heat to activate silver in the print medium.

Pica

A unit of measurement used in the graphic arts industry. One pica equals approximately 1/6 inch.

PICT

A bitmap picture format.

Pincushion Distortion

A distortion where the image compresses toward the center with distortion most noticed at the center of horizontal or vertical edges.

Pixel

A term common in computer imaging referring to a picture element.

Plasma Display

A display screen that has a gas contained between two panels. When specific x-axis (horizontal) and y-axis (vertical) dots on the panels are electrically charged, the gas in that area glows.

Platform

Refers to the particular proprietary computer hardware design. This can be a PC, Macintosh, Sun, mainframe, etc.

Plotter

An output device that generates color images using multiple passes with colored ink.

Plug and Play

The ability to install equipment with little or no training or setup.

PMS - See Pantone Matching System

PMT (Photo Mechanical Transfer)

A print process that uses exposure of an image to a photographically sensitive paper.

PMT (Photo Multiplier Tube)

A device used in scanners and film recorders with a good dynamic range and signal-to-noise ratio.

Point

A unit of measurement used in the graphic arts industry. There are 12 points to a Pica. One point equals approximately 1/72 inch. See "Postscript Point."

Portrait, Portrait Mode

The orientation of an image that is taller than it is wide; a setting controlling an output device to properly fit a computer document to the print medium.

PostScript

A popular page description language language designed by Adobe. See "PDL."

Postscript Point

A slight revision to the "Point" measurement unit. A Postscript point is exactly 1/72 of and inch. Most graphics software utilizes this refined value for a point.

Power PC Chip

A microprocessor chip jointly developed by Apple, IBM and Motorola that has the capability to run commonly used operating systems.

PPD

Refers to PostScript Printing Description, a small file used to describe a particular printers characteristics and capabilities to a graphics or word processing software program.

PPI (Pixels Per Inch)

Often used interchangeably with DPI, PPI refers to the number of pixels per inch in an image.

PPP (Point to Point Protocol)

Software that is typically used to connect a computer to the internet using a modem.

Pre-Flighting

A process of checking a job for possible problems before the job is sent for final output. This process is used to find problems such as missing fonts, postscript errors and color problems.

Prepress

The process of preparing photographic originals, typography, graphics and illustrations for a printing process.

Pressure Sensitive Pen

A tool that allows for information to be put into the computer with a stylus in a manner similar to writing or drawing.

Primary Color

A color that is the basis for all other color combinations. The primary colors are Red, Green and Blue (RGB) in light; Cyan, Magenta and Yellow (CMY) in color photographic printing. In offset color printing, black (K) is added to CMY inks to more accurately reproduce an image.

Print on Demand

This refers to any number of short run publishing processes that include both copier technologies and direct-to-press applications.

Printer Font

Font files that can be reproduced from the output device. These may vary from fonts that are used in desktop computers.

Process Color

The colors Cyan, Magenta, Yellow, plus Black, used for offset printing.

Progressive Scan

A non-interlaced refresh system for monitors that cuts down on CRT flicker.

Proprietary

The design of programs, systems or equipment that are owned by an entity. This technology may be licensed for use in other applications or systems.

Protocol

The steps needed to communicate or activate an operation or exchange of information in or between computers.

Proxy

A representative version or sample of a larger image.

Proxy Image

A low resolution image used in any software programs to show the effects of changes without performing transformations on high resolution files.

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Q

Quantization, Quantizing

An encoding process that allows for the reduction of file size.

Queue

The line of events within the computer or peripheral.

Qwerty

A standard keyboard layout based on the American standard typewriter.

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R

RAID (Redundant Array of Inexpensive Disks)

A performance enhancing group of disks that work together to speed data transfer and access.

RAM (Random Access Memory)

The high-speed portion of the computer's memory that is held on special chips for use in current applications or procedures.

RAS (Remote Access Server)

A server that allows access to various computers through modems.

Raster Image

An image that is defined as a collection of pixels arranged in a rectangular array. See "Bitmap."

Rasterization

Changing vector type image information to raster image information.

Raw Data

Data that is not formatted or processed.

Real-Time

The concept of seeing on the screen the actions of the computer as though the activity were happening at a natural pace.

Red

An additive primary color.

Reflective

Refers to print material that is viewed with the light on the same side of the image as the viewer.

Refresh Rate

The rate at which an image is redrawn on a CRT. This is needed because the phosphors at each pixel are stimulated by the electron gun for only a brief time. The faster the refresh rate, the more stable an image will appear on the screen. A refresh rate of 72 times per second, or 72 Hz, is the standard for digital imaging and is near the limit of the human brain to discern any flickering or instability.

Removable Media

Any storage system that can be removed from the drive such as a Syquest cartridge.

Rendering

Applying shading and lighting effects to a two dimensional image to create the look of a three dimensional object.

Resolution

The particular pixel density of an image, or the number of dots per inch a device is capable of recognizing or producing. See "DPI" and "PPI."

Retouching

Removing imperfections or unwanted portions of an image.

RGB

A color model using red, green, and blue; the additive primary colors. Video display systems use RGB data to create screen images.

RIFF (Raster Image File Format)

A storage format used with gray-scale images.

RIP (Raster Image Processor)

A processor used to convert information from a graphics application into raster data for output on a printer.

RlSC (Reduced Instruction Set Computing)

A computer design that speeds up processing by dividing tasks into smaller computational units.

ROM (Read-Only Memory)

A memory type that cannot be changed or rewritten, and will not lose information when a computer is shut down.

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S

S-RAM CD (Static Random Access Memory CD)

A compact disc that is used to provide storable RAM.

S-VGA (Super Video Graphics Array)

A video display format common to PC's.

Sans Serif

Typefaces that lack serifs. See "serif."

Saturation

The amount of chroma present in a color. Pastels are low saturation while bright colors are said to be highly saturated.

Scan

The process of translating a picture from artwork or transparency into digital information.

Scan Rate (Refresh Rate)

The rate that a display changes its image in a given time.

Scanner (Drum, Flatbed and Slide Scanners)

A device that makes difital image files from original artwork, prints, slides or negatives.

SCODL

A graphics format common to film recorders.

Screen

A halftone screen on film used in conjunction with photographic film or paper to produce a halftone image from continuous tone art.

Screen Angles

In half-tone printing, these are the angles at which half-tone screens are placed to avoid moire patterns on the final image. The most commonly used angles are: Black = 45 degrees; Magenta = 75 degrees; Yellow = 90 degrees; Cyan = 105 degrees.

Screening

The process of using screens or digital methods to create halftone screen representations of continuous tone images.

SCSI (Small Computer Systems Interface)

The "Scuzzie" is a fast interface system that allows peripheral devices to connect with the CPU.

SCSI Chain

The SCSI chain is the linking of SCSI compatible devices such as scanners or storage devices to a computer via a SCSI port. A SCSI chain may contain up to seven devices.

SCSI Port

The connection used by SCSI devices to connect to the CPU. Often SCSI devices are used in a series called a "Scuzzie Chain."

SECAM (System Electronique Couleur Avec Memorie)

The television and video system used in France and Russia.

Separations (Seps)

The actual splitting of an image into the colors that will be used in the printing process. Normally, Cyan, Magenta, Yellow and Black (CMYK) are the separations for 4-color printing.

Serif

The small feet or flared ends at the tips of the strokes, and at the corners or junctions of individual characters in some typefaces. These typefaces are referred to as serif faces.

Server

One computer that acts as a networking device for many interconnected computers

Service Bureau

A company that provides image services such as scanning or output.

SGO (Second Generation Original)

An output from the imaging process producing transparencies or negative that will serve as an original in other operations.

Shade

The brightness or luminance of an image when compared to a gray scale.

Shadow

Detail or information contained in dark areas 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.

Shadowing

The process of copying ROM information into RAM.

Sharpening

A picture enhancement making the image have more distinct borders, areas, lines or tones.

Signature

In offset printing, the printed sheet containing a number of different pages that have been arranged to allow; through folding, trimming, and binding; the creation of a multi-page finished piece.

Silhouetting

A masking or image blocking that isolates and image from the background.

SIMM Chip (Single Inline Memory Module)

Used to add additional RAM memory to computers.

Slide

A mounted 35mm transparency designed for projection.

Smooth

A process that softens, blurs or makes an image, color or pattern to appear out of focus.

SMPTE (Society of Motion Picture and Television Engineers)

An organization that sets standards for the film and television industry.

Sneakernet

Physically moving a diskette or media from one station to another to provide a transfer of information instead of connecting electronically.

Soft Proof

Viewing a digital image with a monitor instead of generating a hard copy proof.

Soft-Edge Masking

A technique used to isolate a portion of an image with an edge that allows for a smoother transition to areas around the masked part.

SPARC (Scalable Process Advanced RlSC Computer or Scalable Performance Architecture)

A RISC workstation designed by Sun Microsystems.

Spatial Resolution

The finest image portion that can be seen at any magnification.

Spectrophotometer

Device used to measure the quality and accuracy of a color monitor and the film or paper output.

Spline Curve (Bezier Curve)

The linking of a series of points on a graph with a smooth curve that is mathematically plotted.

Spooler

A function of the computer that collects output instructions and data before sending them to a printer.

Spot Color

A single color ink used independently in a printed piece, as opposed to a process color which is used in overlapping combinations of other process inks to create any of a large spectrum of colors.

Spread

In offset printing, a term describing a trapping relationship between a foreground element, and a background color or element. To create a trap between a foreground element that knocks out a background, the foreground may be "spread" or slightly enlarged to overlap beyond the knockout originally created by the foreground element. See also "Choke."

Step and Repeat

The process of duplicating an image into a fixed position for use in a printing process. This procedure can take place within a computer prior to printing out hard copy of some sort, or by using large cameras to duplicate an existing original onto photographic film or paper.

Stochastic Screening

A screening process that conveys the tone of a screened image by varying the number and location of dots as opposed to varying just the size of dots within a rigid grid.

Stock Photos

An already existing picture that can be purchased for use instead of having a photograph specifically made.

String

A sequence of bits of data making up a command or file.

Stripping

The process of assembling individual elements to make a composite page for use in the offset printing process.

Stroke

A term referring to a line segment in a graphics program. Lines or "strokes" can be straight or curved, open or closed.

Stylus

A tool that is used on a graphic input tablet as a drawing instrument, or as a mouse.

Sub-Sample

To access and use a small portion of an image file.

Subtractive Primaries

These are the three colors that are used to create all other colors in color photographic printing. (Cyan, Magenta and Yellow)

Superimpose

To place one element over another to create stacking of images or overlays.

SWOP (Standard Web Off-Set Printing)

Refers to a set of standards for conveying and representing color information. This standard is based on the characteristics of web offset presses.

Syquest Cartridges

A particular style of magnetic removable storage disks.

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T

Tablet (Graphics Tablet)

An input device that uses a stylus or specialized mouse to write or draw on the tablet surface to communicate with the computer.

Tape Storage

A mass storage device that uses removable tape as a medium.

TARGA (True vision Advanced Raster Graphics Adapter)

A 24-bit color file format and expansion board developed by ITT / Truevision.

TCP/IP

Transmission Control Protocol/Internet Program. Developed by the Department of Defense, this allows different computer types and platforms to be linked for communicating across a network. Computers on the internet use TCP/IP to communicate with other computers on the internet.

Terabyte

1,099,511,627,776 bytes of computer memory.

Texture Mapping

Putting a texture or image file on the surface of a 3-D computer image.

TGA (TARGA)

An acronym for a Targa board or file.

Thermal Autochrome

An image printing technology developed by Fuji Photo Film that requires no water or chemicals to process. The color dyes are in a special paper and are activated by heat.

Thermal Transfer

A technology that uses heat to deposit dye on a receiver material.

32 Bit Color

A digital image format that incorporates 256 shades in 8-bits for each of three color channels (RGB) and includes a mask (alpha) channel with a possible 256 levels of opacity.

Thumbnail

A small low resolution version of an image.

TIE (Tagged Image Extraction)

A technology that extracts only the part of the image from a server needed for display on a screen. This is used to reduce network traffic when viewing an image.

TIFF (Tagged Image File Format)

A common bitmap image format developed by Aldus. TIFFs can be black-and-white, grayscale or color.

Tiling

Reproducing a large image by breaking the image into parts, or tiles. When pieced together, they reproduce the original image.

Tint

Some percentage of a solid ink. Tints are created by using a screen to create the impression of a lighter color when the ink is printed onto paper or another medium.

Toner

The material deposited on paper or receiver in magnetic electrostatic (non-impact) printing.

Tracking

The adjustment of the overall spacing between all text characters in a word or words.

Transfer Rate

The rate at which data can be transferred, usually expressed as Kilobits per second (Kbps) or bytes per second (Bps).

Transform

A color transformation from one color file system (RGB to CMYK) to another, or changing from one hue base to another.

Trapping

In offset printing, creating a small area of overlap between different colored elements that come into contact with one another on a printed piece to avoid any visible gaps that might arise from slight mis-registration on press.

Trilinear Scanner

A scanning device that uses three linear array charge coupled devices utilizing red, green and blue filters to capture color scans in a single pass.

Tungsten

Metal in filament of bulbs creating illumination when electronically charged. Tungsten= 3200 Kelvin an orange color.

TWAIN

A standard application protocol that allows cross-platform and multi-manufacturer communication from the scanner to the software.

Tweening

Placing between or interpolating the area between pixels.

24-bit Color

A digital color model that uses eight bits each for the three additive colors red, green and blue; creating more than 16 million colors.

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U

UCR (Under Color Reduction)

The removal of cyan, magenta and yellow from neutral color areas (primarily shadow tones) and their replacement with black. The reverse is UCA (Under Color Addition).

UCR (Undercolor Removal)

A type of process color separation which determines the amount of black ink used to replace Cyan, Magenta, and Yellow in areas where those three inks overlap.

Unix

A multi-tasking operating system invented by AT&T and found in powerful computers developed by companies such as Sun MicroSystems, Silicon Graphics, Hewlett-Packard and others. It allows a computer to perform several intensely complex tasks at the same time, even when it involves very large amounts of data, such as would be found in commercial digital imaging environments.

Unsharp Masking (USM)

The sharpening of an image by creating contrast at contrasting edges of the element.

UnZip

To decompress a file (usually text) using PKUNZIP or WinZip, two popular programs. The decompression takes place automatically when a Zip compressed file is opened (See Zip).

URL (Uniform Resource Locator)

This is the address for a given homepage or site on the World Wide Web. Each homepage has its own address and is registered. Generally, a URL will appear like this: http://www.name.com. The last three letters are called an extension: *.com = commercial; *.org = organization; *.edu = educational institution; *.gov = government. Other, less common extensions are also used.

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V

Vaporware

A term referring to "Not-Yet-Released" software.

VAR (Value Added Retailer)

An equipment and software reseller who puts together systems and often provides support services.

VDR (Video Disk Recorder)

A device that records to video disk medium.

VRAM (Video Random Access Memory)

RAM that receives video display data from the software and operating system, and transfers it to the video display hardware.

Vector Image

A computer image that uses mathematical descriptions of paths and fills to define the graphic, as opposed to individual pixels.

VESA

A term used for a local bus.

VGA (Video Graphics Array)

A mid-level resolution video display monitor.

Video Board

An expansion board that processes video signals for display on the monitor.

Video Prints

A print made directly from video output instead of from a computer RIP.

Vignette

A transition from one color or intensity to another.

Virtual Memory

Using a hard drive as (RAM).

Virus

An malicious implant put into software that can cause failures of systems such as data or memory loss.

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W

WAN (Wide Area Network)

A group of computers, LAN's or servers interconnected for broad communications.

Wash

A term meaning to affect color or tint by adding saturation or chroma.

Web Site

Any location on the World Wide Web that can be linked to any other site.

White

The result of combining the additive primary colors (Red, Green and Blue).

White Point

The lightest tone printable in an image. All tone values above this threshold will print as white.

World Wide Web

A part of the internet that allows text, pictures and graphics to be linked and used in a single graphical user interface (GUI).

WORM (Write-Once Read Many Times)

A storage device that uses a medium that once written to can not be written over. Photo CD is an example.

Write

The act of creating, sending or transferring data to an output device or storage.

WYSIWYG (What You See Is What You Get)

A monitor configured to represent the images displayed in a manner consistent with the desired printed result. Pronounced "wizzy-wig."

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X

XA (Extended Architecture)

A specific type of compact disc read only devices that are compatible with the Photo CD format and other CD's. Multiple session Photo CD's cannot be fully utilized on non-XA drives.

X-Windows

The Unix equivalent of Microsoft Windows. Most Unix graphical user interfaces, such as Motif and OpenLook, are based on X-Windows.

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Y

YCC

A color space developed by Eastman Kodak to define colors by luminance (Y) and two levels of chrominance (C and C).

Yellow

A subtractive primary color for color printing and printing. It is made up of equal parts of red and green projected light.

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Z

Zip

To compress a file (usually text) using PKZIP or WinZIP, two popular programs. Commonly used to reduce the size of a file to speed up transmission over the internet or an on-line service.

Zip Drive

A relatively new removable storage device employing a small disk similar in design to a floppy disk, but offering significantly more storage space (approximately 100MB) and speed.

Zoom

Making the image or image part become larger (zooming in) or smaller (zooming out) as it appears on the monitor.

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