Adding Object Detection in ROS 2
The ROS 2 wrapper offers full support for the Object Detection module of the ZED SDK. The Object Detection module is not available for the older ZED camera model.
The Object Detection module can be configured to use one of the available detection models:
|Any objects, bounding box based|
|Any objects, bounding box based, compromise between accuracy and speed|
|Any objects, bounding box based, more accurate but slower than the base model|
|Bounding Box detector specialized in person heads, particularly well suited for crowded environments, the person localization is also improved|
|Bounding Box detector specialized in person heads, particularly well suited for crowded environments, the person localization is also improved, more accurate but slower than the base model|
The result of the detection is published using a new custom message of type zed_interfaces/ObjectsStamped defined in the package zed_interfaces.
Enable Object Detection #
Object detection can be started automatically when the ZED Wrapper node starts by setting the parameter
true in the file
It is also possible to start the Object Detection processing manually by calling the service
with the parameterTrue`.
In both cases, the Object Detection processing can be stopped by calling the service
with the parameterFalse`.
See the services documentation for more info.
Object Detection results in RVIZ2 #
To visualize the results of the Object Detection processing in Rviz2 the new
ZedOdDisplay plugin is required. The plugin is available in the zed-ros2-examples GitHub repository and can be installed following the online instructions.
Note: the source code of the plugin is a valid example of how to process the data of the topics of type zed_interfaces/ObjectsStamped.
Topic: Selects the object detection topic to visualize from the list of available images in the combo box.
Depth: The depth of the incoming message queue.
History policy: Set the QoS history policy.
Keep Lastis suggested for performance and compatibility.
Reliability Policy: Set the QoS reliability policy.
Best Effortis suggested for performance and compatibility.
Durability Policy: Set the QoS durability policy.
Volatileis suggested for compatibility.
Transparency: the transparency level of the structures composing the detected objects.
Show skeleton: Not used.
Show Labels: enable/disable the visualization of the object label.
Show Bounding Boxes: enable/disable the visualization of the bounding boxes of the detected objects.
Link Size: the size of the bounding boxes’ corner lines.
Joint Radius: the radius of the spheres placed on the corners of the bounding boxes.
Label Scale: the scale of the label of the object.