Smoothing of the lines against the background would be a wonderful addition. It makes it easier on the eyes and just makes for a better presence. It's not very difficult to do, I have implemented it in my gesture recognition program. I hope to see it in yours. Just between you and I...Your program is extreamly professional with a world of uses, excellent work!!
This is something that's been suggested before, and has been put on the very-doubtful list, because it would require more system overhead, for no real benefit.