Summary

In preparation for releasing common_msgs as a ROS Stack, we have been making a number of changes to the Message types that reflect the lessons learned through our experimentation with these data structures. Our goal for this release is to make a long-term commitment to these Message types. Although this release represents a large number of changes, future releases will not have these destabilizing changes.

The changes have been summarized below. These changes have been integrated over the course of 2 months or more, though a large number have been made in the weeks prior to the final release.

High-level Summary

• Moved msgs and srvs into single msg packages.
• image_msgs moved into either stereo_msgs or sensor_msgs
• New Image format

• PointCloud had minor changes. It is now in the sensor_msgs package and it's fields are now "points" and "channels", and channels now uses "values" instead of "vals"

• robot_srvs and robot_msgs were eliminated. Messages within them were either moved to other packages or eliminated.

New Image Format

The sensor_msgs/Image format now corresponds closely with OpenCV's CvMat type and is much simplified over the previous representation. The new fields are

encoding

• string representing image encoding - see below

width

• image width

height

• image height

step

• length of one image line in bytes

data

• image data

The possible values of the encoding field are listed in the file "sensor_msgs/src/image_encodings.cpp". These are:

"rgb8"
"rgba8"
"bgr8"
"bgra8"
"mono8"
"mono16"

and "8UC1" through "64FC4" for the OpenCV image types.

as a convenience, an image creator can use the fillImage() function here to construct the Image message:

#include "sensor_msgs/fill_image.h"

fillImage(img_msg,
          sensor_msgs::image_encodings::RGB8,    // encoding
          my_height,                             // height
          my_width,                              // width
          3 * my_width,                          // step
          my_image_data                          // image data
);

Code changes

image_msgs/FillImage.h -> sensor_msgs/fill_image.h

Moved Messages

image_msgs/CamInfo                -> sensor_msgs/CameraInfo
image_msgs/DisparityInfo          -> stereo_msgs/DisparityInfo
image_msgs/RawStereo              -> stereo_msgs/RawStereo
image_msgs/RegionOfInterest       -> sensor_msgs/RegionOfInterest
image_msgs/StereoInfo             -> stereo_msgs/StereoInfo 
laser_scan/LaserScan              -> sensor_msgs/LaserScan
nav_srvs/StaticMap                -> nav_srvs/GetMap
nav_srvs/Plan                     -> nav_srvs/GetPlan
robot_msgs/AttachedObject         -> tabletop_msgs/AttachedObject
robot_msgs/BatteryState           -> pr2_msgs/BatteryState
robot_msgs/CollisionMap           -> mapping_msgs/CollisionMap
robot_msgs/ControllerState        -> pr2_mechanism_controllers/ControllerState
robot_msgs/DiagnosticMessage      -> diagnostic_msgs/DiagnosticArray
robot_msgs/MapMetaData            -> nav_msgs/MapMetaData
robot_msgs/ObjectOnTable          -> tabletop_msgs/ObjectOnTable
robot_msgs/OrientedBoundingBox    -> mapping_msgs/OrientedBoundingBox
robot_msgs/ParticleCloud          -> geometry_msgs/PoseArray
robot_msgs/ChannelFloat32         -> sensor_msgs/ChannelFloat32 ***
robot_msgs/Path                   -> nav_msgs/Path
robot_msgs/PolygonalMap           -> mapping_msgs/PolygonalMap
robot_msgs/Vector3                  -> geometry_msgs/Vector3
robot_msgs/Vector3Stamped           -> geometry_msgs/Vector3Stamped
robot_msgs/Point                  -> geometry_msgs/Point
robot_msgs/PointStamped           -> geometry_msgs/PointStamped
robot_msgs/Pose                   -> geometry_msgs/Pose
robot_msgs/PoseStamped            -> geometry_msgs/PoseStamped
robot_msgs/Transform              -> geometry_msgs/Transform
robot_msgs/Table                  -> tabletop_msgs/Table
robot_msgs/Quaternion             -> geometry_msgs/Quaternion
robot_srvs/SetPoseStamped         -> robot_mechanism_controllers/SetPoseStamped
robot_srvs/KillAndSpawnController -> mechanism_msgs/KillAndSpawnController
robot_srvs/KillController         -> mechanism_msgs/KillController
robot_srvs/ListControllers        -> mechanism_msgs/ListControllers
robot_srvs/SpawnController        -> mechanism_msgs/SpawnController
robot_srvs/SwitchController       -> mechanism_msgs/SwitchController
robot_srvs/StaticMap              -> nav_srvs/GetMap

Changed Messages

robot_msgs/DiagnosticStatus       -> diagnostic_msgs/DiagnosticStatus
 - added hardware_id
 - values changed to diagnostic_msgs/KeyValue
 - strings element deleted
robot_msgs/OccGrid                -> nav_msgs/OccupancyGrid
  - Added header
robot_msgs/PointCloud             -> sensor_msgs/PointCloud
 - pts -> points
 - chan -> channels
 - chan[].vals -> channels[].values
robot_msgs/PoseWithCovariance     -> geometry_msgs/PoseWithCovariance
 - covariance is now defined around fixed axis
 - field renamed from pose_with_covariance to pose
robot_msgs/Polygon3D              -> geometry_msgs/Polygon
 - color was removed
robot_msgs/Twist                  -> geometry_msgs/Twist
 - now uses Vector3 instead of Point
 - fields are now linear and angular
robot_msgs/Wrench                 -> geometry_msgs/Wrench
 - fields are now linear and angular
 - now uses Vector3 instead of Point
robot_msgs/TransformStamped       -> geometry_msgs/TransformStamped
 - changed semantics of parent and child relationship to be consistent
  - parent_id -> header.frame_id
  - frame_id -> child_frame_id
image_msgs/Image                  -> sensor_msgs/Image
  - Image underwent major changes and now aligns with OpenCV's CvMat data structure
image_msgs/CompressedImage        -> sensor_msgs/CompressedImage
  - removed encoding: https://prdev.willowgarage.com/trac/personalrobots/ticket/1915
visualization_msgs/Polyline       -> geometry_msgs/Polygon, nav_msgs/Path, nav_msgs/GridCells
 - Split into 3 messages based on use.  Paths -> nav_msgs/Path, robot footprint -> geometry_msgs/Polygon, and the raw/inflated obstacles -> nav_msgs/GridCells

Replaced Messages

robot_msgs/Acceleration           -> geometry_msgs/Vector3
  - ax, ay, az  -> x,y,z
robot_msgs/AngularAcceleration    -> geometry_msgs/Vector3
  - ax, ay, az  -> x,y,z
robot_msgs/AngularVelocity        -> geometry_msgs/Vector3
  - vx, vy, vz  -> x,y,z
robot_msgs/Velocity        -> geometry_msgs/Vector3
  - vx, vy, vz  -> x,y,z
robot_msgs/PoseDot                -> geometry_msgs/Twist
  - vel and ang_vel               -> linear and angular
robot_msgs/PoseWithRatesStamped   -> nav_msgs/Odometry or sensor_msgs/Imu (for IMU data)
 - completely restructured with covariance added
robot_msgs/DiagnosticValue        -> diagnostic_msgs/KeyValue
 - moved to more general string key/value
robot_msgs/DiagnosticString       -> diagnostic_msgs/KeyValue
 - moved to more general string key/value pair
deprecated_msgs/BaseRobot2DOdom   -> nav_msgs/Odometry
  - completely restructured with covariance added 
image_msgs/ImagePoint             -> geometry_msgs/Point
  - ignore z

New messages

geometry_msgs/Pose2D
geometry_msgs/PoseWithCovarianceStamped
geometry_msgs/PoseWithRates
geometry_msgs/TwistWithCovariance
geometry_msgs/TwistWithCovarianceStamped
geometry_msgs/WrenchStamped
sensor_msgs/Imu

Deprecated

robot_srvs/MoveToPose -> deprecated_srvs/MoveToPose
robot_msgs/VOPose     -> deprecated_msgs/VOPose

Deleted

robot_msgs/PoseDDot (unused)
robot_msgs/PoseWithRates
robot_srvs/GetJointCmd
robot_srvs/SetJointCmd 
robot_srvs/GetValue
robot_srvs/GetVector
robot_srvs/SetVector
robot_srvs/GetQuaternion