thanks, curiouser. I think me or ashkultz can use py2exe to convert your function into something that can be inserted into rasterfarian. Can you make a quick stand-alone py script that takes in a range of overlap 0-to-whatever and input from the pipe and outputs to the pipe in a netpbm format? If that's that at all complicated, any sort of input/output would be fine.
P.S. I'm not sure centering the image is best. If you view the document in landscape and you only have a trailing paragraph on the page, wouldn't it be better for it to go to the middle-top?