Always use image transport even when intra-process comms is enabled

[jasiex01]

Overview

Author: Jan Hernas

Issue

Issue link: #557
Issue description: Image transport now (since Jazzy) supports intra-process communication so there is no need to create a separate publisher when ipc is enabled. I'd like to be able to take advantage of image transport functionalities even when using intra-process comms.

Changes

ROS distro: Jazzy
List of changes:

• Image transport is now a default publisher even when ipc is enabled.

Testing

Hardware used: OAK-D W PRO

Visuals from testing

Launch file used:

<launch version="0.1.1">

  <node_container namespace=""
    name="oak_container"
    pkg="rclcpp_components"
    exec="component_container_isolated">
    <composable_node namespace=""
      name="oak"
      pkg="depthai_ros_driver"
      plugin="depthai_ros_driver::Camera">
      <extra_arg name="use_intra_process_comms" value="true" />
      <param from="$(find-pkg-share raph_bringup)/config/oak.yaml" />
    </composable_node>
    <composable_node namespace="oak"
      name="point_cloud_xyz"
      pkg="depth_image_proc"
      plugin="depth_image_proc::PointCloudXyzNode">
      <extra_arg name="use_intra_process_comms" value="true" />
      <remap from="image_rect" to="stereo/image_raw" />
      <remap from="camera_info" to="stereo/camera_info" />
    </composable_node>
  </node_container>

</launch>

Ros2 topics with image transport plugins and intra-process comms enabled:

[Serafadam]

Hi @jasiex01, thanks for the PR, just a minor question, why was lazy publishing check removed as well?

[jasiex01]

Hi @jasiex01, thanks for the PR, just a minor question, why was lazy publishing check removed as well?

If you are talking about the detectSubscription function - it's because it is no longer used since all image publishing happens via image transport publisher. In the IT publisher the lazy subcription check happens with getNumSubscribers() > 0 check, so lazy publishing is still supported properly.