Owl Slider Image as Background Image

custom.js

    $(document).ready(function() {
      $("#owl-demo").owlCarousel({

      navigation : true,
      slideSpeed : 300,
      paginationSpeed : 400,
      singleItem : true,
      afterInit: afterOWLinit
      });

      function afterOWLinit(elem){
        $.each(this.owl.userItems, function (i) {
          imageUrl = $(".owl-wrapper").children().eq(i).find("img").attr("src");
          $(".owl-wrapper").children().eq(i).css('background-image', 'url(' + imageUrl + ')');
          imageUrl.hide();
        });
      }
      
    });