参考链接：
https://blog.csdn.net/chenxingwangzi/article/details/48825767
https://www.cnblogs.com/cj2014/p/4007165.html
https://www.ncnynl.com/archives/201703/1440.html
https://blog.csdn.net/yangtze_1006/article/details/51569251
博主已经事先安装好了ROS Indigo，那我们先安装安装openni2_camera
udo apt-get install ros-indigo-openni2-camera
再安装openni2_launch
sudo apt-get install ros-indigo-openni2-launch
在ROS下启动Xtion
方法一：使用rviz启动
新终端，执行roscore
roscore
新终端，执行openni2_launch
roslaunch openni2_launch openni2.launch
新终端，实时观看rgb、深度、点云
rosrun rviz rviz
add camera、pointcloud2 选择正确的topic就可以实时看到xtion返回的数据了 （这里我还没实现）
方法二：使用命令行启动
roslaunch openni2_launch openni2.launch
rosrun topic_tools mux /camera/image_raw /camera/rgb/image_raw
rosrun image_view image_view image:=/camera/image_raw
方法三：在rqt窗口启动
打开终端
roscore
打开终端
roslaunch openni2_launch openni2.launch
打开终端，执行
rqt
在“rqt”窗口中选择 “Plugins” -> “Visualization” -> “Image View“
在选择框中选取你想看的图像类型，如
/camera/rgb/image_rect_color
/camera/depth/image
方法四：
roscore
roslaunch openni2_launch openni2.launch
rosrun rqt_image_view rqt_image_view