graphics, file format (GIF89a) A variant of the
GIF 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.
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)