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2017-09-28 11:12:13 -0600 answered a question Calculate relative 3D position from points in stereo images?

You've got all the information from the stereo calibration to construct an image_geometry::StereoCameraModel. You could

2017-09-28 11:00:07 -0600 answered a question Camera Pose Calibration Valid_Pattern_Ratio_Threshold and Circle Spacing

The pattern_distance is the distance between two neighbouring circles (be aware to be consistent with units of length th

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2017-03-28 08:12:10 -0600 answered a question Parameters for camera_pose_calibration

It's all in accordance with OpenCV:

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2016-06-22 05:00:33 -0600 answered a question I could not install camera_pose_calibration.

Hi Prashant,

You can do an extrinsic calibration with the new camera_pose_calibration package. This new package does support indigo. More information about the usage of this package can be found at

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2015-09-16 05:44:21 -0600 asked a question TF error in ar_track_alvar

I am running ar_track_alvar to find a marker bundle (using a Kinect 2). The following error occurs:

[ros.ar_track_alvar]: ERROR InferCorners: "ar_marker_0" passed to lookupTransform argument source_frame does not exist.

With rostopic echo /ar_pose_marker I get the list of found marker bundles. There is only one marker bundle present in the real world. However, always two marker bundles are found. The found marker bundles are identical (same marker ID, and exactly the same pose), except for the frame_id. One marker bundle frame id is kinect2_rgb_optical_frame and the other found marker bundle frame id is empty.

I would assume that only one marker bundle should be published (the one with the frame id filled in) and that the error comes from the marker bundle without a frame ID.

I am running ar_track_alvar/findMarkerBundles with this command:

rosrun ar_track_alvar findMarkerBules 5.5 0.08 0.2 /kinect2/hd/points /kinect2/hd/camera_info kinect2_rgb_optical_frame 10 cube.xml

Does anyone know why this error occurs? And how to solve it?

Why are two (identical) marker bundles published, and one with an empty frame id?

This issue does not occur when I use the option to find individual markers instead of marker bundles. The issue is also present when I use another camera (Asus Xtion).

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2015-06-25 10:01:56 -0600 commented answer Package for Panasonic Robots

Thank you for your reply and suggestion. I have sent the question to the ROS-Industrial mailing list.

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2015-06-25 05:46:05 -0600 asked a question Package for Panasonic Robots

I am looking for a package with drivers, desciption and utilities for Panasonic (welding) robots. I have not found such a package. Is there some kind of package that I can use for Panasonic robots?

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2015-03-10 08:28:37 -0600 commented answer How can I get extrinsic camera parameters from the ROS camera_calibration package

Even after reading this: I still don't see an option to get the camera extrinsics.

2015-03-10 08:27:14 -0600 commented answer How can I get extrinsic camera parameters from the ROS camera_calibration package

Thank you for your answer. This may indeed be an option to get the extrinsic parameters as well. However, I think that the ros calibration_package also contains the extrinsic camera parameters. I just don't know how to get the extrinsic camera parameters from these four matrices (D, K, R and P).

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2015-03-06 05:11:48 -0600 asked a question How can I get extrinsic camera parameters from the ROS camera_calibration package

I want to get more a more accurate point cloud and uv-mapping for the Softkinetic Depthsense by calibrating the intrinsic and extrinsic parameters of the depthsense using the ROS camera_calibration package.

The output matrices of the camera_calibration package are: 1) Distortion parameters (D) 2) Intrinsic camera matrix (K) 3) Rectification matrix (R) 4) Projection matrix of the processed (rectified) image (P)

The Depthsense SDK has the option to set the camera parameters in the StereoCameraParameters struct.

How do I get the camera pose (extrinsic parameters) from the camera_calibration output (D, K, R and P)?

The projection matrix (P) contains is the projection onto the rectified image. Decomposing this matrix into a translation and rotation would give the extrinsic parameters of the virtual, rectified camera. What I need to set in the Depthsense SDK are the real camera extrinsics.

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2014-09-30 09:09:20 -0600 answered a question Exception in camera_calibration with Bumblebee

It is solved by using the package pointgrey_camera_driver to publish the Bumblebee2 images. The images will be published in the layout that camera_calibration expects.

2014-09-30 07:20:17 -0600 commented answer Exception in camera_calibration with Bumblebee

I was indeed using custom code.

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2014-09-30 06:47:04 -0600 commented answer Exception in camera_calibration with Bumblebee

The encoding is indeed different. The pointgrey_camera_package is publishing /camera/left/image_raw with bayer_grbg8 encoding. I was publishing and using /camera/0/intensity with bgr8 encoding before.

2014-09-30 04:05:59 -0600 commented answer Exception in camera_calibration with Bumblebee

There are no problems with camera_calibration if I use the package pointgrey_camera_driver to publish the Bumblebee2 images. I think that you are right that the published topic I was using did not have the layout that was expected by camera_calibration.

2014-09-30 02:48:01 -0600 commented question Exception in camera_calibration with Bumblebee

All dependencies were installed with rosdep install camera_calibration, but unfortunately that did not solve it. I got exactly the same error.