Where can I download high quality images of poker cards?
The deck linked by @Glorfindel is for French playing cards.

Here's a link to poker playing cards, in PNG or SVG format.

Poker cards are wider than French ones. This design is used by many decks, e.g. Bicycle Playing Cards, and will typically be the one you see in movies or at the casino.




  A full set of poker playing cards created using vector graphics. The
  .SVG source for each card is available as well as a high resolution
  rasterized .PNG version. These images are released into the public
  domain - attribution is appreciated but not required.


Here's the related blog post : Byron's Blog - Vector Playing Cards

As mentioned by @Dezza, there  are other alternatives:


  There's also SVG sets by revk at me.uk/cards with associated blog
  posts revk.uk/search/label/Playing%20cards