I can export a Google Document through this URL, and then getting its content:
https://docs.google.com/feeds/download/documents/export/Export?id=DOC_ID&exportFormat=html
But the problem is that there's no way of telling when a page starts or ends. The HTML does not wrap each page in its own div, not does each element's class describe their page number.
What I'm trying to do is just extract the text and images from a Google Document, while knowing what page the text and images are on. I don't really care about anything else.