It goes without saying
that you should get your image into the state
that you want to import before you import it.
So, if the image has excessive white space
surrounding the picture area,
you might want to crop the pdf/eps/whatever —
perhaps using a simple command line tool like
but of course that’s optional,
and outside of the scope of this question.
- Import it into Inkscape, using the poppler library option.
- Save as an Enhanced Metafile (EMF).
- Import the EMF file into Microsoft Word.
emf is a vector format that Word can handle,
so it does not pixelate, and so it does retain quality,
unless the original image has qualities
that emf cannot reproduce because of its limitations.
Keep in mind that emf cannot cope with some shapes, gradients and fonts
that eps/pdf/whatever can cope with.
Even if this works and you maintain the vector-ness of the image,
something may be lost due to the lousy format of emf.