How to export PIL Image from matplotlib

Does anyone know how to do the following:

Having created a plot in matplotlib, export the plot's image
to a PIL image, so that the bytes of the PIL image can be
manipulated further in python, i.e, stored, inserted into a
pdf in reportlab, and so on. i.e, How do we do this without
doing savefig() to a temporary file, then reading the file
back again with etc?