color - Normalizing hematoxylin and eosin-stained histology images

This is a medically related question...Most pathology slides are stained with hematoxylin (blue) and eosin (red). However, every lab does it differently. I would like to take a bunch of images from various sources and get the staining properties to all be about the same--with some automatable process, since I have 100's of images to deal with.

Any theories?

Thanks,