You will need Python Imaging Library (http://www.pythonware.com/products/pil/) to run the script.

Usage:
Following will fetch the GML with gml_id 
from http://000000book.com/data and render it to output.png
$ python GMLImageRenderer.py -id gml_id output.png 

Following will load a local GML file named file.gml and render it to output.png
$ python GMLImageRenderer.py -file file.gml output.png