I need to do a hit test on a PNG, but not on the original image. I have an image of a model's face, and I need a hit test for her lips, her cheeks, her eyes etc. This would be done by drawing other objects over parts of her face, e.g. an ellipsoid type shape over her lips. Doing a hit test on that would be quite easy, but resizing that if the face image resizes, or moving that if the face image moves is what is worrying me.
What are my options here?