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Overview

This package contains launch files for using OpenNI-compliant devices such as the Microsoft Kinect in ROS. It creates a nodelet graph to transform raw data from the device driver into point clouds, disparity images, and other products suitable for processing and visualization.

Starting with ROS Hydro, all the functionality of openni_launch has been moved to rgbd_launch, in order to allow other drivers such as libfreenect (freenect_launch) to use the same code. openni_launch itself contains 1 launch file:

• launch/openni.launch - Launch RGB-D processing through rgbd_launch with the OpenNI driver.

Quick start

Launch the OpenNI driver. This will launch the full constellation of nodelets:

roslaunch openni_launch openni.launch

To visualize in rviz:

rosrun rviz rviz

Set the Fixed Frame (top left of rviz window) to /camera_depth_optical_frame.

Add a PointCloud2 display, and set the topic to /camera/depth/points. Turning the background to light gray can help with viewing. This is the unregistered point cloud in the frame of the depth (IR) camera. It is not matched with the RGB camera images.

Alternatively you can view the disparity image:

rosrun image_view disparity_view image:=/camera/depth/disparity

Now let's look at a registered point cloud, aligned with the RGB data. Open the dynamic reconfigure GUI:

rosrun rqt_reconfigure rqt_reconfigure

And select /camera/driver from the drop-down menu. Enable the depth_registration checkbox.

Now go back to rviz, and change your PointCloud2 topic to /camera/depth_registered/points. Set Color Transformer to RGB8. You should see a color, 3D point cloud of your scene.

Again, you can view the registered disparity image:

rosrun image_view disparity_view image:=/camera/depth_registered/disparity

To view the color image from the RGB camera outside of rviz:

rosrun image_view image_view image:=/camera/rgb/image_color

or to view the grayscale image:

rosrun image_view image_view image:=/camera/rgb/image_mono

Launch files

openni.launch

Launches in one process the device driver and many processing nodelets for turning the raw RGB and depth images into useful products, such as point clouds. Provides default tf tree linking the RGB and depth cameras.

Arguments

This section only covers arguments that are specific to openni_launch. There are also some common arguments that can be supplied to openni.launch that are documented with rgbd_launch.

camera (string, default: camera)

• Descriptive name for your device. All published topics are pushed down into the <camera> namespace, and this also affects tf frame ids and some node names. If you are using multiple cameras, use this argument to disambiguate them.

Device driver

device_id (string, default: #1)

• Specifies which device to open. The following formats are recognized:

  • #1	Use first device found
    2@3	Use device on USB bus 2, address 3
    B00367707227042B	Use device with given serial number

rgb_camera_info_url (string, default: file://${ROS_HOME}/camera_info/${NAME}.yaml)

• Calibration URL for the RGB camera. By default, looks in your ROS home directory for calibration identified by the device serial number, e.g. $HOME/.ros/camera_info/rgb_B00367707227042B. If no calibration is found, uses a default camera model with a typical focal length and distortion unmodeled.

depth_camera_info_url (string, default: file://${ROS_HOME}/camera_info/${NAME}.yaml)

• Calibration URL for the IR/depth camera. By default, looks in your ROS home directory for calibration identified by the device serial number, e.g. $HOME/.ros/camera_info/depth_B00367707227042B. If no calibration is found, uses a default camera model with the focal length reported by OpenNI and distortion unmodeled.

depth_registration (bool, default: false)

• If true, use OpenNI's factory-calibrated depth->RGB registration.

load_driver (bool, default: true)

• If true, load the OpenNI device driver. Set to false if raw data is provided by another source, e.g. bag file playback.

tf frames

rgb_frame_id (string, default: /<camera>_rgb_optical_frame)

• The tf frame id of the RGB camera.

depth_frame_id (string, default: /<camera>_depth_optical_frame)

• The tf frame id of the IR camera.

publish_tf (bool, default: true)

• If true, publish the default (uncalibrated) tf tree. Set to false if extrinsics are provided by another source, e.g. calibration or bag file playback.

tf_prefix (string, default: "")

• If set, this tf_prefix is prefixed to all frame ids used/generated by openni.launch

Remapping

rgb (string, default: rgb)

• Remap the rgb namespace.

ir (string, default: ir)

• Remap the ir namespace.

depth (string, default: depth)

• Remap the depth namespace.

depth_registered (string, default: depth_registered)

• Remap the depth_registered namespace.

projector (string, default: projector)

• Remap the projector namespace.

Launch configuration

debug (bool, default: false)

• If true, launches nodelet manager in GDB for debugging.

respawn (bool, default: false)

• If true, enables bond topics between nodelet loaders and the managers and respawns any nodes (manager or loader) that die. This makes the system robust to any node dying, but the proliferation of bond topics can overwhelm introspection tools like rxgraph.

num_worker_threads (int, default: 4)

• Sets the number of worker threads in the nodelet manager

This section only covers arguments that are specific to openni_launch. There are also some common arguments that can be supplied to openni.launch that are documented with rgbd_launch.

Published Topics

Please consult the documentation at rgbd_launch.