Hide images and place as background-images

img-background.js

/* 
* Image as background
* Hide images and place as background-images
* Author: Franco Moya - @iamravenous
*/

document.addEventListener("DOMNodeInserted", function() {
  var imgSrc = document.querySelectorAll("[data-img-src]");

  for (var i = 0; i < imgSrc.length; i++) {
    var imgUrl = imgSrc[i].getAttribute('src');
    var imgParent = imgSrc[i].parentNode;

    if (imgUrl && imgParent.hasAttribute('data-img-parent')) {
      imgSrc[i].style.display = 'none';
      imgParent.style.backgroundImage="url('" + imgUrl + "')";
    }
  }
}, false);