PIL + bump map

[Nagy László Zsolt]

I'm a newbie to Python Imaging Library. I searched for something like 
Bump Map in Gimp but I could not find a solution.
It would be the best to have the same filter in PIL but I can live with 
something similar that gives me 'elevation' feeling on
a smooth gradient image. My task is to split several 6000x4800 pixel 
image into many smaller regions and apply differents
effects on them. So I cannot use Gimp because there are thousands of 
images. Please give me a point to start with.
Many thanks.

   Laci 1.0