Only released in EOL distros:   fuerte

Nodes

april.ros.TagPublisher

ROS Wrapper for publishing tags using the April Tag Detection Library

Subscribed Topics

image_raw (sensor_msgs/Image)

• Image stream to be used for tag detection

camera_info (sensor_msgs/CameraInfo)

• Camera info message corresponding to the image stream

Published Topics

tags (april_msgs/TagPoseArray)

• Tag information based on detected tags

/visualization_marker_array (visualization_msgs/MarkerArray)

• Rviz markers corresponding to detected tags

/tf (tf/tfMessage)

• Tag information published on the tf tree

Parameters

~tag_family (string, default: "april.tag.Tag36h11")

• The family of tags to be detected

~tag_size (double, default: 0.095)

• Tag size (in meters) required to project the tag in 3d space. Different sizes for different tag ids are currently not supported.

~use_camera_info (bool, default: true)

• Use focal length values from the corresponding camera_info message or not

~focal_length_x (double, default: 485.6)

• Focal length in the x axis (in pixels). This value is used if ~use_camera_info is set to false

~focal_length_y (double, default: ~focal_length_x)

• Focal length in the y axis (in pixels). This values is used if ~use_camera_info is set to false. This value is typically equal to the focal length in the x axis.

~publish_visualization (bool, default: true)

• Publish visualizaion for easy tag display in rviz

~tag_vis_magnification (double, default: 1.0)

• Magnify the size of the visualized tag by this amount to make visualization in rviz easier

~broadcast_tf (bool, default: true)

• Broadcast detected tags on the tf tree. Nodes reading tag information from the tf tree can use this package interchangeably with the ar_pose package.

~seg_sigma (double, default: 0.8)

• Detector parameter. See library documentation/research paper for more details.

~sigma (double, default: 0.0)

• Detector parameter. See library documentation/research paper for more details.

~min_mag (double, default: 0.004)

• Detector parameter. See library documentation/research paper for more details.

~max_edge_cost (double, default: 0.5236)

• Detector parameter. See library documentation/research paper for more details.

~mag_thresh (double, default: 1200.0)

• Detector parameter. See library documentation/research paper for more details.

~theta_thresh (double, default: 100.0)

• Detector parameter. See library documentation/research paper for more details.

~error_bits (int, default: 1)

• Detector parameter. See library documentation/research paper for more details.

~weight_scale (int, default: 100)

• Detector parameter. See library documentation/research paper for more details.

~seg_decimate (bool, default: false)

• Detector parameter. See library documentation/research paper for more details.

~debug (bool, default: false)

• Detector parameter. See library documentation/research paper for more details.

Usage

Running the node directly (with default parameters)

rosrun april_tags_node execute

Using roslaunch

roslaunch april_tags_node april_tags_node.launch

Running rviz

rosrun rviz rviz -d `rospack find april_tags_node`/config/rviz.vcg

roslaunch april_tags_node rviz.launch

Report a Bug

This package just serves as a wrapper for the APRIL toolkit. If you detect a bug in the wrapper, please report it on the repository page(http://code.google.com/p/utexas-ros-pkg/issues/list). If you find a bug in the APRIL toolkit, please contact the original developers.