如何滑动来自http url的图片？

<div id="image-container"></div>

#image-container {
  width: 500px;
  height: 300px;
  overflow: scroll;
}

var imageUrl = "http://example.com/image.jpg";
var container = document.getElementById("image-container");

container.style.backgroundImage = "url('" + imageUrl + "')";

container.addEventListener("scroll", function() {
  var scrollPosition = container.scrollLeft + "px " + container.scrollTop + "px";
  container.style.backgroundPosition = scrollPosition;
});