apriltag_draw
ROS package for drawing apriltags on image
README
ROS Apriltag drawing package
This repository has a ROS2 component for drawing apriltags onto an image. You will find this package handy when trouble shooting apriltag detection problems. The node in this package is usually launched from a launch file in the apriltag_detector package. Refer there for more information.
Components
apriltag_draw::ApriltagDraw
Topics (subscribed):
tags
: the detected tags from the apriltag library.image
: the image from which the tags were detected. Must be synced withtags
, i.e. identical header time stamps in both streams.
Topics (published):
image_tags
: image with the tags drawn onto
Parameters:
image_transport
: What image transport to use (defaultraw
)qos_profile
: What profile to use for subscribing to images. Allowed aresensor_data
anddefault
. Defaultdefault
.max_queue_size
: How many images or tag detections to keep. Default: 200.
Launch files
draw.launch.py
Arguments:
camera
: name of the camera, e.g./camera_0
. Default:camera
.image
: name of the image underneath the camera node, e.g.image_raw
. The node will then subscribe to images/camera_name/image_raw
. Default:image_raw
.image_transport
: the transport to use, e.g.compressed
,ffmpeg
etc. Default:raw
.
composable.launch.py
This launch script has identical arguments to draw.launch.py
, but is implemented as a composable
node for illustration purposes.
Example usage
ros2 launch apriltag_draw draw.launch.py image_transport:=ffmpeg camera:=/cam_sync/cam3
Will create a node using the compressed ffmpeg image transport, using the following topics,
and publishing an image under /cam_sync/cam3/tags
.
Subscribers:
/cam_sync/cam3/image_raw/ffmpeg: ffmpeg_image_transport_msgs/msg/FFMPEGPacket
/cam_sync/cam3/tags: apriltag_msgs/msg/AprilTagDetectionArray
Publishers:
/cam_sync/cam3/image_tags: sensor_msgs/msg/Image
/cam_sync/cam3/image_tags/ffmpeg: ffmpeg_image_transport_msgs/msg/FFMPEGPacket
License
This software is issued under the Apache License Version 2.0.