Hairline: A .25 point rule. The thinnest
Halftone: The screening of a continuous tone
photograph so that it may be reproduced. The dots merge to create
the illusion of continuous tone.
Hard Dot: A dot that is sharp and has no
distortion when reproduced.
High Key: An image that mainly consists of
highlights and midtones.
Highlight: The lightest or whitest part in a
photograph represented in a halftone.
Horizontal Scale: The alteration of the
horizontal dimension of characters without changing their height.
HSB: Hue, Saturation, Brightness. A color
model where 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 monitor in three channels, (hue, saturation, and
HTTP: HyperText Transfer Protocol.
Hue: In color, the ability to perceive the
main attributes of color by using the human eye.