I emailed Mike Clifton with some questions regarding any type of image/library built in support with lua in AS. Unfortunately it won't be that easy to do but I still think it might be possible. It just means I will have to work harder to pull it off.
I need to check out the "open with gimp" script and see if in the meantime I can use that to link the current frame sequence image directly to Gimp. So you would create the sequence in Gimp, load it into an image layer with my layer script, then activate a button script on any frame and it would open that frames image in Gimp.
This would be a temp solution until or if I can figure out how to save images from AS using lua.
-vern