function getImageNaturalSizes(image, callback) {
  // Modern browsers (except Safari)
  if (image.naturalWidth && !IS_SAFARI_OR_UIWEBVIEW) {
    callback(image.naturalWidth, image.naturalHeight);
    return;
  }

  var newImage = document.createElement('img');

  newImage.onload = function () {
    callback(newImage.width, newImage.height);
  };

  newImage.src = image.src;
}
Get an image's natural sizes.
@param {string} image - The target image.
@param {Function} callback - The callback function.