ImageMap类型重复自身

Question

我在我的网站上发布了一个图像地图类型，但如果您放大并缩小图像，图像会自动重复。我正在使用的平台是Joomla。编辑是JCE编辑。这是它在我的网络http://logic.al/qtu2/index.php/maptest中的样子。我在这里缺少什么？

var moonTypeOptions = {
  getTileUrl: function(coord, zoom) {
      var normalizedCoord = getNormalizedCoord(coord, zoom);
      if (!normalizedCoord) {
        return null;
      }
      var bound = Math.pow(2, zoom);
      return 'http://i.imgur.com/9iGCzkv.png' +
          '/' + zoom + '/' + normalizedCoord.x + '/' +
          (bound - normalizedCoord.y - 1) + '.png';
  },
  tileSize: new google.maps.Size(1130, 604),
  maxZoom: 3,
  minZoom: 0,
  radius: 1738000,
  name: 'Moon'
};

var moonMapType = new google.maps.ImageMapType(moonTypeOptions);

function initialize() {
  var myLatlng = new google.maps.LatLng(0, 0);
  var mapOptions = {
    center: myLatlng,
    zoom: 5,
    streetViewControl: false,
    mapTypeControlOptions: {
      mapTypeIds: ['moon']
    }
  };

  var map = new google.maps.Map(document.getElementById('map-canvas'),
      mapOptions);
  map.mapTypes.set('moon', moonMapType);
  map.setMapTypeId('moon');
}

// Normalizes the coords that tiles repeat across the x axis (horizontally)
// like the standard Google map tiles.
function getNormalizedCoord(coord, zoom) {
  var y = coord.y;
  var x = coord.x;

  // tile range in one direction range is dependent on zoom level
  // 0 = 1 tile, 1 = 2 tiles, 2 = 4 tiles, 3 = 8 tiles, etc
  var tileRange = 1 << zoom;

  // don't repeat across y-axis (vertically)
  if (y < 0 || y >= tileRange) {
    return null;
  }

  // repeat across x-axis
  if (x < 0 || x >= tileRange) {
    x = (x % tileRange + tileRange) % tileRange;
  }

  return {
    x: x,
    y: y
  };
}

google.maps.event.addDomListener(window, 'load', initialize);