What software are you using for the Vision engraver ? if it is Engravelab then it has a tool to produce a vector of your jpeg/bitmap image (look at help on Accuscan). Many other packages have this either as a standard function, or add on to the package.

Otherwise use Corel / Adobe Illustrator or a 3rd Party service as advised

Dr Engrave that comes with Roland machines has the ability to import a .bmp and cut it.

My first practice cut was a Cadillac logo that I saved from their website as a .jpg and converted it to .bmp

I thought it was pretty slick being a newbie to engraving.

If only my computerized mat cutter was as easy...