How would I go about creating an animation in GIMP which gives the following result: The animation starts with an annulus at the centre of a transparent background, which then enlarges until it disappears off the edge of the image entirely? Say the "thickness" of the annulus is 20 pixels. Is this even possible?
I guess I could echieve the result if I could at least create an animation which enlarged a circle from 0 radius to a radius equal to max(width/2, height/2) of the image. I could then subtract two such animations to get my animated annulus. However, I'm not even sure how to do the enlarging circle animation !