Create a layered OpenRaster image from TMX Map Format (Tiled)

Why?
For a game i need a large number of pre rendered images..
Tiled help's a lot to create the visuals for the game but i need to add final touch on them.

Why OpenRaster?
As of version 2.8 Gimp can open this image file format.. Also is the native format of MyPaint

Requirements:
PythonMagick, ElementTree

On Ubuntu 13.10
sudo apt-get install python-lxml python-pythonmagick

Limitations:
Only one tileset, Layer data as CSV Alpha code... stay tuned...