Animated GIF File Format

The animated GIF (aGIF) graphic format is derived from the standard, non-animated GIF graphic format. An aGIF file contains a number of still images in a specified order, and we call these still images frames. For all these frames, a unified size for the animation space is set. Each frame contains information on the movement of its upper left corner within the animation. A display period and a redraw method are also defined for each frame.

The frames of aGIF files can have their own "local" color palettes, which have a color depth (i.e. amount of memory used for color information) of 1, 4, or 8 bits, just like the GIF format itself. The maximum number of colors in the palette is, therefore, 256. If no local palette is set for a frame, the global palette is used. One local or global color of your choice can be set as transparent.

The GIF format also allows the addition of supplementary text information, with unlimited length, to pictures or animations.

Timeline for This Animation Example

loop
  Image 1 - 150 ms
  Image 2 - 150 ms
  Image 1 - 150 ms
  Image 3 - 150 ms

Note: This example uses a picture from the Zoner Clip Art collection.