# Glossary

additive primary colors
  The colors of red, green and blue (RGB) - which give the perception of white when combined equally. These are the colors of the color system used by monitors and scanners.

application
  A software program that helps you carry out a particular task, such as word processing, image editing, or financial planning.

bi-level data
  Image data that is composed of 1 bit per pixel. A pixel is represented by a single bit of digital data that can be expressed as only 1 (light) or 0 (dark).

bit
  Short for binary digit. It is the smallest unit of data in computer processing. A bit can represent one of two values: on, represented by a 1, or off, represented by a 0.

bit/pixel
  The unit that indicates the number of bits allocated for a pixel. The larger the bit value, the more detail of a pixel will be reproduced.

brightness
  A scanner function to lighten or darken the output image data.

byte
  A unit of information consisting of eight bits. A byte can represent a control code or character.

carriage
  A component of the scanner that contains the optical sensor and light source for scanning.

color correction
  A method of adjusting the color image data for a particular type of device so that the reproduction results are as close as possible to the original colors.

color separation
  A process of converting full-color images into a limited number of primary colors. Additive primary colors (red, green, and blue) are used by the scanner, and the subtractive primary colors (cyan, magenta, and yellow) plus black are used for printing press separation.

color space
  A method that reproduces a specific color. Additive primary colors (red, green, and blue) are used by the scanner, and subtractive primary colors (cyan, magenta, and yellow) plus black are used for printing press separation.

default
  A set of values used when no other selections have been made. These are sometimes called factory defaults if the original values have not been changed since the scanner left the factory.

descreening
  A scanner function to remove moiré patterns.

dithering
  A process in which software or an output device simulates continuous tones with groups of dots.

document
  The item, such as a sheet of paper or a book, that is placed into the scanner to read.

dpi
  Short for dots per inch. This is a unit of measurement for resolution. The higher the value is, the higher the resolution becomes.

DTP
  Desktop Publishing system, a system that enables you to edit publications on a computer.

ESC/I
  Short for EPSON Standard Code for Image scanners. It is a system of commands that allows you to control image scanners from your software.

ESC/P
  Short for EPSON Standard Code for Printers. It is a system of commands that allows you to control printers from your software.

exposure
  A scanner function that lightens or darkens the scanned image data.

gamma
  A value that expresses the relationship between the input and output of a device. By adjusting the gamma, the brightness of the mid-tones of an image can be changed without affecting the shadows and highlights.

grayscale
  Images represented with various shades of gray in addition to black and white.

halftoning
  A method of reproducing images with patterns of dots to improve the quality of the output.

home position
  The position at the rear (nearest the cover hinge position) of the scanner where the carriage rests before a scanning operation.

ICM
  Short for Image Color Matching. It is a Windows color management system designed to help you get WYSIWYG (what you see is what you get) color output. This software displays colors on your screen as they exist on the scanned documents, or prints colors as you see them on your screen.

IEEE 1394
  Short for Institute of Electrical and Electronics Engineers 1394. It is a hardware interface for connecting high-speed peripherals such as scanners, hard drives, and others. You can connect multiple IEEE 1394 devices simultaneously in either a daisy chain or tree configuration.

impact dot printer
  A printer that transfers ink onto the paper by striking an ink ribbon with a number of small pins.

ink jet printer
  A printer that transfers ink onto the paper by spraying the ink through a number of small nozzles.

interface
  A piece of hardware, a method, or a standard used for connection between or among computer devices.

Internet
  A worldwide network of computers and communication devices, the largest of its kind, originally conceived as a research project of the US government. The Internet is composed of many different types of connections, including electrical and fiber optic cabling as well as wireless communications.

IP address
  Short for Internet Protocol address, a numeric address which uniquely identifies a computer connected to a network using TCP/IP, such as the Internet. See also Internet and TCP/IP.

LAN
  Short for Local Area Network, a computer network on which the attached devices are in close proximity (such as within the same office or building).

laser printer
  A printer that uses a laser and the electrophotographic method to print a full page at a time. The laser is used to "paint" a charged drum with light, to which toner is applied and then transferred onto paper.

line sequence
  A type of color scanning that separates primary colors line by line. The carriage makes only one pass.

marquee
  A moveable and adjustable frame that marks the area of an image that will be previewed or scanned.

moiré
  A cross-hatch pattern that appears on scanned images when printed materials are scanned. It is a result of interference that occurs due to the difference between the pitches of the scanning and the halftone screens.

monochrome
  Black and white images, or images represented only by the intensity of luminosity.

OCR
Optical Character Recognition.
  The technology that allows computers to "read" text from physical objects. OCR requires a graphical representation of text to interpret, which usually comes from a scanned image.

pixel
  Short for picture element. Each image is composed of a number of pixels. Pixels are also counted in units of dots.

plain bi-level
  Bi-level image data without the halftoning process.

port
  An interface channel through which data is transmitted between devices.

preview
  A scanner function that allows you to see the effects of most EPSON Scan settings, and to make additional image adjustments before scanning.

primary colors
  Basic colors. See additive primary colors and subtractive primary colors.

reflective document
  A document printed on opaque materials, such as publication, printed paper, and photo.

resolution
  Indication of how finely an image is resolved into pixels. It can be measured in dots per inch (dpi), pixels per inch (ppi), or samples per inch (spi).

scan
  An operation performed by the sensor and the carriage. The image is divided into pixels when scanned.

scanning area
  The physical size of the image that can be scanned by the scanner.

sRGB
  A standard color space used as the default color space within the Windows color management system (ICM 2.0).

subtractive primary colors
  The colors of cyan, magenta, and yellow (CMY) that produce black when mixed in certain amounts. In printing, black is often added to give more definition as mixing of actual inks cannot produce pure black.

TCP/IP
  A widely used family of protocols for communicating data between computers in a network.

threshold
  A reference point that is used to determine whether data will be processed as "on" or "off". In the case of color image data, "on" means that a certain color will appear in a pixel or dot, and "off" means that color will not appear there.

tone correction
  A method of adjusting the tone curve so that the reproduction results on different types of output devices have gradations similar to the original image.

tone curve
  The graph that shows the contrast ratio between the input (original image) and output (image data) in image processing.

unsharp mask
  Originally a photographic process in which a sharply focused and a slightly out-of-focus image are combined to produce a sharper image. This process is simulated by software to produce the same effect.

USB
  Short for Universal Serial Bus. It is a hardware interface for connecting peripherals such as a keyboard, mouse, scanner, or printer to the computer.

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