you are not terribly clear about how things are done in your code,
What sort of clarification do you need?
but in this case if you draw ONTO the image you are rotating
Image.getGraphics and whatnot, it would work
Image.getGraphics will not show anything drawn outside of the image boundaries. As I stated in the OP, often times the overlaying image will overlap those boundaries, thus making it not a good solution.
I did, for whatever reason, put that as BufferedImage.getSubImage which isn't really relevant nor what I mean... oops
I'll take the math please!