Copyright: Can I use images of heroes / cards for a free PVZ guide on Android?

Hi,

I would like to know if it's possible to use images from the game to write a free PVZ guide for Android. I simply would like to give some information about the game for beginners and show all the heroes with their skills and cards that they can possibly play. 

I haven't found any contact details and eventually I ended up here. If anyone can provide me contact details or even an answer about this question I would be very thankful. 

I've read that it's generally not allowed except if EA specifically says it's ok. But I have no idea how to get a permission. I have however seen many guides etc. so I believe it shouldn't be a problem.

Thanks!