I was experimenting tagging some images and closest I could find is adding a repeating group in front of the picture and giving some kind of a grid based system to the user to play with. I just highlight the selected area, but you can do more stuff with it. See the demo below:
It is not very hard, since the grid is simply 10x10 repeating group.
In order to create an empty 10x10, I had to use a list with this plugin:
I have tested it with custom state as well. There is a big speed difference:
You can see the example editor here: Tests for Forum 11 | Bubble Editor