Web Design in a Nutshell, 2nd Edition

Creating Animated GIFs

Regardless of the tool you choose, the process of creating an animated GIF is about the same and involves making decisions about a standard set of features and options. Some of the following descriptions use GIFBuilder’s terminology, but the concepts and settings are consistent across tools.

Frame Delay

Also called “interframe delay,” this setting specifies the amount of time between frames. Frame delays are measured in 1/100ths of a second. You can apply a different delay time to each frame in the animation to create pauses and other timing effects. This differs from digital video formats, in which the delay between all frames is consistent.

Transparency

You can set transparency for each frame within an animation. Previous frames will show through the transparent area of a later frame if disposal methods are set correctly.

If the background frame is made transparent, the browser background color or pattern will show through.

Warning

There is a bug in early versions of Navigator in which transparency works only with background patterns, not colors specified in HTML.

Don’t be surprised if the transparent areas you specified in your original graphics are ignored when you import them into a GIF animation utility. You may need to set transparency in the animation package. Some standard transparency options include:

None

No transparency.

White

All the white pixels in the image will become transparent.

Based on first pixel

The color of the “first pixel”—that is, ...