How to use image_proc node
Using Xtion on Ubuntu with ROS hydro. Ran openni2_launch to the launch camera drivers.
$ rostopic list
/camera/rgb/image_raw
/camera/rgb/camera_info
and many other topics /camera/depth/.. camera/ir/..
ROS_NAMESPACE=camera rosrun image_proc image_proc
tells me to advertise /camera/image_raw first.
I was assuming my camera drivers are publishing to /camera/image_raw and camera/camera_info by default which I suppose image_proc will subscribe to publish image_mono or image_rect image but apparently they are publishing /camera/rgb/image_raw and camera/rgb/camera_info. What is the difference between /camera/image_raw and /camera/rgb/image_raw and how should I publish /camera/image_raw.