animated GIF

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)