How to extract vectors from a PDF file?

You can use Inkscape, which is a free, open source and cross-platform vector graphics application. It will allow you to import the PDF files and select embedded vectors:

_{Image from here.}

You can then edit the vectors and process as you like.

General documentation is available on the Inkscape website. Details about PDF importing can be found here:

• PDF in Importing other File Formats — Inkscape Beginners' Guide 1.0 documentation
• Time for action — importing a PDF into Inkscape – O'Reilly's book Inkscape by Bethany Hiitola, chapter 3

Note that on Linux it like requires X11. There is also a native Windows version.

Alternatively, you may want to give Adobe Illustrator a go (paid software).

While Inkscape is an awesome way to do it, for those lacking X11, you can also extract individual pages of a PDF into SVG format using the poppler-utils at the command line. For example, to extract just page 30:

$ pdftocairo -f 30 -l 30 -svg  somehugemanual.pdf  myextractedpage.svg

You can then use your favorite vector editor (mine is Inkscape) to isolate the image from the text.

Alternately, if you're a hardcore command-line user, you can extract to EPS (encapsulated postscript) and use sed to hide all the text (which happens to be between BT and ET lines for pdftocairo). Here's how:

$ pdftocairo -f 30 -l 30 -eps  manual.pdf  - | sed '/^BT$/,/^ET$/ d' > myimage.eps

And, if you're really insane to avoid using X11, you can even shrink the bounding box of the image from the command line using Ghostscript's eps2eps command:

$ eps2eps myimage.eps myimage-bb.eps

I've tested this and it works great. However, personally, I find it easier to just use Inkscape.

You can use Affinity Designer (paid, not a subscription, you have to pay for every major version), which is available for Windows and Mac.