Install Xtion2

Spec

Spec/Device Xtion2
Optimized Range 0.8 - 3.5m
RGB Image Size 5MP (2592x1944)
Depth Image Size
VGA (30FPS)
QVGA (30FPS)
Field of View
74° horiz
52° vert
90° diagonal

Install SDK && Try Sample

# Download SDK.zip from https://www.asus.com/3D-Sensor/Xtion-2/HelpDesk_Download/
cd ~/Downloads
tar xf ASUS-Linux-x64-OpenNI2.2.tar.gz
cd ASUS-Linux-x64-OpenNI2.2/

sudo apt-get install ros-$ROS_DISTRO-openni2-launch ros-$ROS_DISTRO-openni2-camera libopenni2-dev
sudo ./install.sh
# you need to copy libSenDuck.so by manual
sudo cp ASUS/Xtion2/lib/libSenDuck.so /usr/lib/OpenNI2/Drivers/

cd Samples/Bin
./SimpleViewer  # This should open a viewer for depth image

Use Xtion2 camera with openni2_camera ROS package

cd ~/ros/$ROS_DISTRO/src
wstool set ros-drivers/openni2_camera https://github.com/ros-drivers/openni2_camera.git --git -v 0.2.8 -y -u

source /opt/ros/$ROS_DISTRO/setup.bash
catkin b

source ~/ros/$ROS_DISTRO/devel/setup.bash
roslaunch openni2_launch openni2.launch