|Note: This tutorial assumes that you have completed the previous tutorials: Camera Frames.|
|Please ask about problems and questions regarding this tutorial on answers.ros.org. Don't forget to include in your question the link to this page, the versions of your OS & ROS, and also add appropriate tags.|
Locating Calibration PatternsDescription: This tutorial covers how calibration patterns can be located.
Tutorial Level: BEGINNER
Next Tutorial: Workspace Calibration Hand-Eye Calibration
The NxLib uses calibration patterns for a number of different purposes. If your camera sees such a calibration pattern, you can locate it with the locate_pattern action (ensenso_camera_msgs/LocatePattern).
This action captures a new image pair. If you didn't explicitly set any of the lighting parameters, the node will automatically turn on the front light for that. It then searches for calibration patterns in those images and estimates their pose, which is reported in the result of the action.
The camera node only considers patterns that are visible in both cameras, because patterns that were seen by only one of the cameras are not useful for any of the provided actions. When only one of the cameras sees a pattern, this will be reported as no pattern found.
Calibration patterns can be used for workspace and hand-eye calibrations. The camera node provides special actions to perform these calibrations. See the tutorials on workspace and hand-eye calibration for more information.
The pattern_marker script can create RViz markers for any detected calibration pattern.