谷歌地图img标记得到透明像素

Question

我使用Google Maps JS API v3将图像标记放在地图上。

以下是JSFiddle的问题说明：

http://jsfiddle.net/t99ars8L/1/

/*
 * declare map as a global variable
 */
var map;

/*
 * use google maps api built-in mechanism to attach dom events
 */
google.maps.event.addDomListener(window, "load", function () {

  /*
   * create map
   */
  var map = new google.maps.Map(document.getElementById("map_div"), {
    center: new google.maps.LatLng(33.808678, -117.918921),
    zoom: 14,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  });

  /*
   * create infowindow (which will be used by markers)
   */
  var infoWindow = new google.maps.InfoWindow();

  /*
   * marker creater function (acts as a closure for html parameter)
   */
  function createMarker(options, html) {
    var marker = new google.maps.Marker(options);
    if (html) {
      google.maps.event.addListener(marker, "click", function () {
        infoWindow.setContent(html);
        infoWindow.open(options.map, this);
      });
    }
    return marker;
  }

  /*
   * add markers to map
   */
  var marker0 = createMarker({
    position: new google.maps.LatLng(33.808678, -117.918921),
    map: map,
    icon: "http://html.accuraten.com/doubleup-html/public/img/map-marker@2x.png"
  }, "<h1>Marker 0</h1><p>This is the home marker.</p>");
});

当您在非Retina桌面屏幕（例如OSX / Safari）上打开此代码并来回缩放时，您可以在此标记上看到透明像素。

看起来像这样 http://i304.photobucket.com/albums/nn185/vladgenie/%20%202015-11-16%20%2012.51.13_zpspjir2ip5.png

为什么会这样？有没有解决方法？