Backstretch - jQuery plugin - responsive background image plugin
Backstretch is a simple jQuery plugin that allows you to add a dynamically-resized, slideshow-capable background image to any page or element. The image will stretch to fit the page/element, and will automatically resize as the window/element size changes. http://srobbin.com/jquery-plugins/backstretch/
Backstretch on GitHub: https://github.com/srobbin/jquery-backstretch
Other references:
https://css-tricks.com/perfect-full-page-background-image/
OR change the image via @media query
use different images for @media query
https://teamtreehouse.com/community/how-to-create-a-responsive-div-with-a-background-image
OR CSS
http://stackoverflow.com/questions/12609110/responsive-css-background-images