H&J: Hyphenation and Justification. The arrangement of text evenly in a column (justification), usually requiring the breaking of words at their appropriate syllable breaks (hyphenation). For this feature, desktop publishing programs include large dictionaries which instruct where hyphens can be correctly placed.
Hairline: A .25-point rule.
Half Duplex: Data communications mode which permits transmission in both directions, but only in one direction at a time.
Halftone: The production of continuous-tone artwork, such as a photograph, through a screen that converts the image into dots of various sizes. When printed, the dots merge to give an illusion of continuous tone to the naked eye.
Handshake: A flow-control, or "go-ahead" signal sent by a local computer to a remote computer when working with a communications program. XON/XOFF is the standard software handshaking method, although it can't be used with remote systems that use a hardware handshaking method.
Hanging Indent: The first line of a paragraph specified to start to the left of the other lines in the paragraph.
Hard Copy: A printed paper copy of output in readable form. It is also a transparency film or photograph of an image displayed on the monitor.
Hard Disk: A mass storage device for digital data. One or more magnetic platters in a single casing, it can store data more precisely and access it more quickly than other forms of magnetic storage.
Hard Dot: see "soft" dot.
Hash Table: A computer data structure that performs a mathmatical calculation on a field identifier (called a hash) to determine where a data element in a large table or index is located.
Header: Text that appears at the top of every page of a document when it is printed.
Hex: Short for Hexadecimal. Counting system using the base 16 - 10 digits and six letters. In hexadecimal notation, the decimal numbers 0 through 15 are represented by the decimal 0 through 9 and the alphabet digits A through F.
Hierarchial: A form of document or file structure, also known as a tree structure, where all elements except the root have parents, and all elements may or may not have children.
High Density: Floppy disks which have been manufactured for high capacity. High-density 5-1/4'' disks hold 1.2 megabytes; 3-1/2'' floppy disks hold 1.4 megabytes.
High Key: An image that mainly consists of highlights and midtones.
High Resolution: Basically, any image that is displayed in better quality by increasing the number of dots, or pixels, per inch than normal. Usually refers to better quality computer displays, but can describe printer quality as well. Called hi-res, for short.
Highlight: The lightest or whitest part in a photograph represented in a halftone reproduction by the smallest dot or absence of dots in the highlight. The highlight should have no color cast.
Highlight Intensification (Catchlights): The ability of a scanner to electronically remove all printing dots in a highlight area in order to boost the contrast. Specular highlights in chrome, gloss and other highly reflective surfaces are the only areas effected. Tonal gradations are not effected except in the specular highlight area. Highlights brighter than those that are to be dropped out will also be dropped. Highlights lower than the intended highlights to be dropped out may also be somewhat effected.
HMA: High Memory Area. The first 64K of extended memory. This area is used by some applications.
Horizoning: The process of aligning a transparency to the angle required by the mechanical to advoid the need for image rotation on the system later.
Horizontal Scale: The alteration or horizontal dimension in characters without changing height.
HSB: Hue Saturation Brightness. To artists, it is an abbreviation for all of a color's characteristics: hue (the pigment); the saturation (the amount of pigment); and brightness (the amount of white included). With the HSB model, all colors can be defined by expressing their levels of hue, saturation and brightness in percentages.
HSL Image: A red, green, blue (RGB) image displayed on a video monitor in three channels (hue, saturation, brightness), although only one channel is displayed at a time.
HTTP: HyperText Transfer Protocol. The TCP\IP-based communications protocol developed for use on the WWW, HTTP defines how clients and servers communicate over the Web.
Hue: In color, the ability to perceive the main attributes of colors by using the human eye. Sometimes the ability to perceive the correct hues are altered by the lighting, or a room containing other colors, or imperfections or diseases of the eye. Standardization of lighting for viewing color is necessary and will correct many of the problems in hue perception.
Hue Error: The difference between the printed color and the ideal color which it is supposed to represent. For example, cyan ink used in four-color process work should ideally reflect all the green and blue frequencies of light that fall on it, while it should absorb all of the red frequencies. In reality, the ink will not achieve this state of perfection.
Hyphenation: Two classes of hyphenation are used in preparing documentation: editorial and typesetting. Editorial hyphenation considers hyphenation for compound words and prefixes; judgements are made on context and standard use of the language at a given time. Typesetting hyphenation considers the breaking of words by syllable at the end of lines to create an elegant text design.
Hypo: An abbreviation for sodium thiosulfate or sodium hyposulfate, a chemical used to fix the image on a photographic film after the latent image has been developed.