In computer graphics, the undesirable jagged
or stair-stepped appearance of diagonal lines in computer-generated
graphic images
Anti-Aliasing
The automatic removal or reduction of stair-step
distortions in a computer-generated graphic image
App
short for application
Application
The use of a computer for a specific purpose,
such as writing a novel, printing payroll cheques, or laying out text
and graphics of a newsletter. This term is also commonly used nowadays
to refer to the program which is used to perform the task. e.g. a
Word Processing Application
Bit
Binary digiT, The basic unit of information
in a binary numbering system. Binary digits consist of 1's and 0's.
The 1's and 0's are equivalent to on and off in a computer system
Browser
an application such as Internet Explorer,
Netscape Navigator or Opera that enables you to traverse or "browse"
the virtual on-line worlds of the Internet
CGI
Computer Generated Images. This term is
most widely used in the movie industry, where CGI allows the creation
of scenes, or even complete movies, that were impossible to create
only a few years ago
Compression
A special format for a file that minimises
the storage space required. Image compression is the use of a compression
technique to reduce the size of a graphics file, which consumes inordinate
amounts of disk space. There are two types of compression, lossy or
lossless
Dither
The adjustment of adjacent pixels of different
colours to give the illusion of a third colour
Dots per inch (dpi)
A measure of printer resolution that counts
the dots that the device can produce per linear inch. Screen resolutions
usually state resolutions in horizontal pixels by vertical lines,
rather than stating a dpi figure
File size
The amount of disk space that an image
takes up
Image
A computer generated picture (usually either
in printed form or digital form on your computer screen)
Image size
the physical dimensions of an image (height
x width)
Layers
Most modern graphics programs allow you
to use layers. These are the computer equivalent of the clear acetate
sheets used in cartooning. You can place an object, or a series of
related objects on different layers. You can change the order of the
layers, to move objects behind or in front of other objects. You can
lock layers to prevent accidentally moving objects. You can also turn
off or hide layers to allow you to concentrate on a certain section
of your drawing at a time
Palette
In computer video displays, the repertoire
of colours that the system is capable of displaying. VGA colour displays
offer a palette of 262,144 colours, although each screen can display
a maximum of 256 colours simultaneously
Pixel
The smallest element (a picture element)
that a device can display on-screen and out of which the displayed
image is constructed
Pixels per inch (ppi)
The number of pixels in a linear inch,
usually reserved for describing the resolution of a computer monitor
or graphic image
Raster Graphics
The display of graphic images using a collection
of small, separate dots called a bit map. The graphic's resolution
is limited by the capabilities of the display or printing device.
Synonymous with bit-mapped graphic. Adobe PhotoShop is a popular image
editor that rasterises images that it opens
Rendering
The process of converting a 3D model, which
is basically just a file which contains descriptions and vectors for
objects, lights and cameras which make up a scene. During the rendering
process, the program can add realistic textures to the objects, calculate
the shadows cast by the various lights and create an image which can
be indistinguishable from the real thing. The better rendering programs
can also include effects such as fog or mist, and even simulate the
depth of field effect produced by a camera lens
Resolution
A measurement-usually expressed in linear
dots per inch (dpi), horizontally and vertically-of the sharpness
of an image generated by an output device such as a monitor or printer
Vector Image
an image that is made up of mathematical
formulas. The image can be scaled up or down without losing quality.
Adobe Illustrator and Macromedia Freehand are two popular products
that can create vector images
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