GIF89a ==>
Animated GIF
<graphics, file format> (GIF89a) A variant of the GIF image format, often
used on World-Wide Web pages to provide moving icons and banners.
The GIF89a format supports multiple "frames" that give the impression of motion
when displayed in sequence, much like a flip book. The animation may repeat
continuously or play once.
Animated GIFs aren't supported by earlier web browsers, however the first frame
of the image is still shown.
There are many utilities to create animated GIFs from a sequence of individual
GIF files. There are also utilities that will produce animated GIFs
automatically from a piece of text or a single image.
One problem with this format is the size of the files produced, as they are by
definition a sequence of individual images. Apart from minimising the number of
frames, the best way to decrease file size is to assist the LZW compression by
using blocks of solid colour, avoid dithering, and use fewer colours. If areas
of an image don't change from one frame to another, they don't need to be
redrawn so make the area a transparent block in the second frame.
(1999-08-01)
Nearby terms:
Anglo-Saxon point « angry fruit salad « ANI «
Animated GIF » animation » Animus » ANL
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