Glossary

ADOBE ACROBAT READER

View and print millions of documents on the web with the free Adobe Acrobat Reader. Reader lets you view ant print PDF files on all major computer platforms.

ALPHA CHANNEL

A special 8-bit grayscale channel used for saving a selection in PhotoShop.

ANTI-ALIAS

The blending of pixel colors along the perimeters of hard-edged shapes, such as type. to smooth undesirable jagged edges.

AUTOMATIC FEED

One way in which paper can be fed into the printer when the sheet feeder is used.

BIT

Binary Digit is the smallest unit of information on a computer. Eight bits equal one byte.

BIT DEPTH

The number of pixels used to store a pixel’s color information on a computer screen.

BITMAP

The display of a picture on a computer screen via the geometric mapping of a single layer of pixels on a rectangular grid. In PhotoShop, Bitmap is also a one-channel mode consisting of black and white pixels.

BYTE

The basic unit of storage memory. One byte is equal to eight bits.

CMYK

Cyan, Magenta, Yellow, and Black are the four colors of ink used in process printing. Cyan, Magenta, Yellow are the three substantive primaries. When combined in their purest forms, they theoretically produce black. Actually they produce a dark, muddy color. CMYK colors are simulated on a computer screen using additive colors.

CONTRAST

The degree of difference between lights and darks in a picture. A high contrast picture is comprised of only the lightest and darkest pixels.

CROP MARKS

Short, fine lines placed around the edges of a page to designate where the paper is to be trimmed by a print shop.

DCS

Desktop Color Separation, is a file format in which a color picture is broken down into five PostScript files: Cyan, Magenta, Yellow, and Black for high resolution printing, and an optional low resolution PICT file for previewing and laser printing.

DIGITIZE

To translate flat art or a transparency into computer-readable numbers using a scanning device and scanning software.

DISK

A carrying medium for processing, reading, and storing electronic files, such as a hard drive, floppy disk, or CD-ROM disk.

DPI

Dots Per Inch is a unit used to measure the resolution of a printer. DPI is sometimes used to describe the input resolution of a scanner, but ppi or “sampling rate” is a more accurate term.

DUOTONE

A grayscale picture printed using two plates for added tonal depth. A tritone is printed using three plates. A quadtone is printed using four plates.

EPS

An EPS is an Encapsulated PostScript format. It is the most reliable format for putting images on paper or film. PostScript is a powerful object-oriented page-description language. There are several programs you can save an image as an EPS. The most common programs are QuarkExpress, Adobe Illustrator, and PhotoShop.

FONT

A typeface in a distinctive style, such as Futura Bold Italic.

GIF

GIF, or Graphics Interchange Format, is a compressed graphics format. It is commonly used to upload documents to online services and to pass documents between other types of computers. PhotoShop is able to save this format. GIF is a compressed format that is a compressed format that is designed to minimize file transfer time over phone lines. (GIF allows animations, transparency, is limited to 256 colors-eric)

GIGABYTE

A unit of memory equal to 1,024 megabytes.

GRAYSCALE

A picture containing black, white, and up to 256 shades of gray, but no color.

HUE

The wavelength of light of a pure color that gives a color its name, such as red or blue, independent of its saturation or brightness.

INK JET

A color printer in which four colors of ink are forced through small holes to produce dots.

JPEG

Joint Photographic Expert Groups compression economizes the way data is stored and identifies and discards extra data not essential to the display of the image. It is referred to as lossy. This means that once an image has been compressed and then decompressed, it will not be identical to the original image. In most cases it is indistinguishable.

KILOBYTE

A unit of 1,024 bytes.

LPI

Lines Per Inch, halftone frequency and screen frequency. The unit used to measure the frequency of rows of dots on a halftone screen.

MEGABYTE

A unit of memory equal to 1,024 kilobytes.

PAGE ORIENTATION

The direction of print on the page. Printing across the width of the page is called portrait orientation. Printing across the length of a page is called landscape orientation.

PDF

Adobe’s Portable Document Format (PDF) is the open de facto standard for electronic document distribution worldwide. PDF is a universal file format that preserves all the fonts, formatting colors and graphics of any source document, regardless of the application and platform used to create it. PDF files are compact and can be shared, viewed, navigated, and printed exactly as intended by anyone with a free Adobe Acrobat (R) Reader. You can convert any document to PDF, even scanned paper using Adobr Acrobat 4.0 software.

PICT

The PICT format tackles graphic images on an object level as opposed to a bitmap level. The biggest problem with PICT format is its unreliability in several respects. For example, line widths can change when moving a picture from one program to another, and text spacing can change.

PIXELS

Picture elements are the individual dots used to display a picture on a computer screen.

PRINTABLE AREA

The area of a sheet of paper on which a printer can reproduce text or graphics, the printing area is smaller than the paper. (The printer’s have pre-set margin minimums you cannot erase-eric)

RAM

Random Access Memory is the system of a computer used for running an application, processing information, and temporary storage.

RESOLUTION

The fineness of detail of a digitized image (measured in pixels per inch) a monitor (measured in pixels per inch - usually 72 ppi), a printer (measured in dots per inch), or halftone screen (measured in line per inch).

SCAN

To digitize a slide, photograph, or other artwork using a scanner and scanning software so it can be displayed, edited, and output from a computer.

TIFF

The Tag Image File Format is another form of bitmap. It is used to exchange documents between applications and platforms.

Programs such as Illustrator, Quark, and Photoshop work together. For example if an image is drawn or composed in Illustrator we can then take that file and open it in Photoshop where the image can be saved either as an EPS, PICT, JPEG, TIFF, or GIF.

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This is information I printed a long time ago from Canon Print Planet, which still exists at http://printplanet.canon.com but this page is no longer on-line. There was no author or copyright declarations on the page.