How do i get the a PointCloud with Intensity from asus xtion?

Hello, i am trying to implement a real-time depth based obstacle detection with a asus xtion camera. I want to use the pcl library (http://pointclouds.org/) for detecting and clustering. Now i am trying to get the example code to run http://pointclouds.org/documentation/tutorials/conditional_euclidean_clustering.php#conditional-euclidean-clustering. My problem is, that the clustering algorithm is based on the points intensity but i dont know how i can get the needed format from the camera. I am using the openni2 driver to run the camera. For this algorith i need the PointCloud format. I am subscribing on the /camera/depth_registered/points topic for getting the sensor_msg::PointCloud2. Then i am using pcl::fromROSMsg to get the PointTypeXYZI format, but the problem is that this topic does not have the intensity information.