Generate Relief Map

Is there anyway I can generate a displacement map with Blender?

What Im trying to do is to automatically generate a depth map from a normal map without using a 2 million polygons model, and base the depth map generation on the normal map texture so I can batch process all the object and use relief mapping on every object.

Anyone one have an idea how I can do script that?

(with nodes maybe?)

Tks in advance,

Cheers,

have a look at this

does it help

http://www.blender.org/features-gallery/features/feature-videos/?video=displace_modifier

nah… not really, the idea is that I have some diffuse texture and I want to auto generate normal map (not a problem) and from this normal map I want to generate a depth map (problem).

And I need to make this process automatic (like part of an exporter or something)