Aruco

• Aruco marker detection and pose estimation.
• Multi marker pose estimation.
• Detection is not affected by lighting conditions.
  • Can be used for low light marker traking.

Documentation

• API documentation can be generated using Doxygen

Usage ROS

• The ROS package is called "maruco" to void collision with the already existing aruco package.

• To install in your ROS project simply copy the aruco folder into your catkin workspace and execute "catkin_make" to build the code.

• To test with a USB camera also install usb-camera and camera-calibration from aptitude to access and calibrate the camera.

• Parameters

  • debug
    • When debug parameter is se to true the node creates a new cv window to show debug information.
    • Default false
  • use_opencv_coords
    • When set opencv coordinates are used, otherwise ros coords are used (X+ depth, Z+ height, Y+ lateral)
    • Default false
  • cosine_limit
    • Cosine limit used during the quad detection phase. The bigger the value more distortion tolerant the square detection will be.
    • Default 0.8
  • theshold_block_size
    • Adaptive theshold base block size.
    • Default 9
  • min_area
    • Minimum area considered for aruco markers. Should be a value high enough to filter blobs out but detect the smallest marker necessary.
    • Default 100
  • calibrated
    • Used to indicate if the camera should be calibrated using external message of use default calib parameters
    • Default true
  • calibration
    • Camera intrinsic calibration matrix as defined by opencv (values by row separated by _ char)
    • Ex "260.3_0_154.6_0_260.5_117_0_0_1"
  • distortion
    • Camera distortion matrix as defined by opencv composed of up to 5 parameters (values separated by _ char)
      • Ex "0.007_-0.023_-0.004_-0.0006_-0.16058"
  • marker###
    • These parameters are used to pass to the node a list of known markers, these markers will be used to calculate the camera pose in the world.
    • Markers are declared in the format marker###: ""
      • Ex marker768 "0.156_0_0_0_0_0_0"

• ROS Subscribed topics

  • topic_camera
    • Camera image topic
    • Default "/camera/rgb/image_raw"
  • topic_camera_info
    • Camera info_expects a CameraInfo message
    • Default "/camera/rgb/camera_info"
  • topic_marker_register
    • Register markers in the node
    • Default "/marker_register"
  • topic_marker_remove
    • Remove markers registered in the node
    • Default "/marker_remove"

• ROS Published topics

  • topic_visible
    • Publishes true when a marker is visible_false otherwise
    • Default "/visible"
  • topic_position
    • Publishes the camera world position relative to the registered markers as a Point message
    • Default "/position"
  • topic_rotation
    • Publishes the camera world rotation relative to the registered markers
    • Default "/rotation"
  • topic_pose
    • Publishes camera rotation and position as Pose message
    • Default "/pose"

Dependencies

• Opencv 2.4.9+
  • Previous versions of opencv 2 might cause problems.
• CMake
• ROS (indigo and later)
  • cv-bridge

License

• MIT license (Available on GitHub page)