Import pdf resolution

Hi all,

I’m using the OmniGraffle Pro 7.3.1. I’m wanting to import pdfs to OG for annotation. It does really well at importing text-based PDFs- multi page files import as individual Canvases. But when it’s text-based, it loses all graphic info. When it’s graphic based (scans of paper), the resolution is so low in OG that it’s unusable.

Is there some way to import a mixed pdf file (scanned paper with OCR) so that the text is recognized as-is, but the graphic elements are imported with a decent resolution?