Hey @melphiz6 you could use a slider and set it to display in the background (100vw for width, 100vh for height) and then apply the technique used here with Autoplay on the slider turned off (just delete the arrows & the nodes to change slides).
http://forum.webflow.com/t/different-slider-each-time-the-page-loads/21720?u=waldo
This should achieve the desired effect. 
Please let me know if you have any questions.
Thank you!
Waldo