[poppler] API: Help getting PDF page into pixbuf

[Angus March]

I need to have a PDF as an image, but the API documentation is very
sparing with information, and I have some questions:

   1. Do I use poppler_page_render_selection_to_pixbuf () to do this?
   2. Assuming 1. is true, do I get page from
      poppler_document_new_from_file(), and the PopplerDocument instance
      from poppler_document_new_from_file()?
   3. How do I interpret the data in pixbuf, or is that for another manual?
   4. Can selection be made from the data returned by
      poppler_page_get_size()?
   5. What's a "Poppler selection style" and what difference does it
      make for this function?
   6. I don't know what glyph_color and background_color should be.
      Isn't that sort of thing native to the PDF document?