Export Settings Editor
The export settings dialog allows for setting parameters for exporting the animation as a GIF file
Transparency color
GIF does not actually provide an alpha channel for transparency, like PNG does. Instead it uses a color palette with a maximum of 256 slots out of which one color is marked as the transparent one.
By default, a certain hue of pink is selected to be made transparent. The color can be changed by selecting a new one from the color chooser dialog or it can be disabled completely by clicking the button, in which case the image changes from a square in the selected color to an X image.
Ditering quality
GIF only allows for 256 different colors per frame. However, images often contain more than this amount of distinct colors, in which case the frame in question needs to be dithered. Dithering essentially means to replace several similar colors by just one color, which will make the resulting image to look more or less grainy.
The dithering quality control allows for adjusting the trade off between graininess and speed of encoding. A lower value will result in better quality images, but will slow down encoding speed considerably. Dithering quality does not have an effect on decoding.
Repeat animation
This control may be used to specify how often the animation will loop, if at all. A value of -1 will show the animation exactly once, that is, the decoder will stop as soon as the last frame is displayed. A value of 0 loops for ever, displaying the first frame again, after the last one is done. Any other value will simply display the animation, the specified amount of times.
For example, if the animation consists of the three frames A, B and C, the following will be the result:
ABC (for -1)
ABCABCABCABC... (for 0)
ABCABC (for 1)
ABCABCABC (for 2)