Animation Properties Dialog Box - Animation Colors

Palette Colors

Global Browser Palette uses the 216 colors of the Netscape Navigator/Internet Explorer palette. This is probably gives the best results for graphics that use a lot of colors and that you want to display in a browser.

Global Optimized Palette is best for graphics that use relatively few colors. You can specify how many colors to include in the graphic. You may need to experiment to get the best results. This option usually gives the smallest file size.

Optimized Palette per Frame often gives the best results as the palette includes the best colors for each frame. You can specify how many colors are included in each palette. Because each frame has its own palette, this option can produce the largest files.

There is an issue with Optimized palette per frame with Macintosh web browsers. Unfortunately they all seem to have a serious bug that prevents per frame optimization working. If you know your audience consists of Mac viewers then we advise you not to use per frame palette optimization.

Number of colors in palette

(This option is available only when using optimized palettes.) For simple graphics you can reduce the number of colors in the palette. This can produce much smaller files without losing quality. You may need to experiment to find the right balance between file size and quality.

Dithering

You can select between three types of dithering with these options. Choosing None means there no dithering, Ordered uses an ordered (regular) dithering pattern and Error diffusion uses error-diffused dithering (a more complex dithering technique). In general, Error diffusion gives the best results, but to only use dithering when really necessary as it prevents the file compression working so well and so makes files larger.

If you turn off dithering, you'll find the images contain perfectly flat areas of color, but where you have graduated color, you will almost certainly see 'steps' because without dithering there aren't enough colors to accurately represent your drawing. You may need to experiment to obtain the right effect.

You cannot use Ordered dithering with an optimized palette.

Make background transparent

Select this to make the bitmap see-through where there are no objects ("Transparent GIF").