How can I take high-quality screenshots of a PDF without ImageMagick using Python?

I would like to automate the process of taking screenshots of a PDF file's pages. I want to be able to specify the zoom (optional) so that the overall image size can be controlled. I would also like to be able to specify the dpi of the screenshots being saved.
Sample PDF file can be found at this link.
I have already tried opening the file with selenium web driver (Firefox), but the scrolling is not supported for rendered PDF files, apparently. Is there a way to render this PDF file and then use any image processing module like Pillow or Open-CV to take the screenshots, or any module that does it directly?