Feature request: Adding /tag_detections_image topic

[kgallowa]

Thanks for the nice work on this package! I was able to get everything working, but I noticed that the running node doesn't publish to a /tag_detections_image topic like the ROS1 version (from AprilRobotics/apriltag_ros) does for helpful visualization. Any plans to add that?

[christianrauch]

The apriltag_ros node only processes AprilTags and publishes the tag poses and raw AprilTag detections. There is a dedicated apriltag_viz node that uses the raw detections and publishes a visualisation on topic tag_detections_image.

This is intentional to keep the core processing node small. Since both noes implement the rclcpp::Node interface, you can put them into the same process with minimal / no IPC overhead. You could write a custom launch script that behaves like the ROS1 node and combines both as ComposableNode in a single ComposableNodeContainer.

[kgallowa]

Great; thanks! I hadn't seen the apriltag_viz package. Makes sense to keep those functions separate.