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ankitdhall / lidar_camera_calibration

ROS package to find a rigid-body transformation between a LiDAR and a camera for "LiDAR-Camera Calibration using 3D-3D Point correspondences"
http://arxiv.org/abs/1705.09785
GNU General Public License v3.0
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Few questions for setup #16

Closed robo7man closed 6 years ago

robo7man commented 6 years ago

Setup: Velodyne and Point Grey Cameras in Stereo setup.

  1. Is there an ideal distance between camera-lidar and the markers. Right now my markers are detected only when close( 3ft-4ft away).

  2. There seems to be different values of projection matrix in conf/config_file.txt 

    611.651245 0.0        642.388357 0.0
0.0        688.443726 365.971718 0.0
0.0        0.0        1.0        0.0

and the corresponding data/zed_left_uurmi.ini in aruco_mapping. 

projection
6.8230856098675258e+02 0 6.2940856933593750e+02 0 
0 6.8230856098675258e+02 3.8939595031738281e+02 0 
0 0 1 0

Is it intentional or is there something more to this?

Thanks!

ghost commented 6 years ago

I think you need to adjust line 2 to line4 in config_file.txt. They are x-,x+; y-,y+ and z-, and z+. Those numbers limit the cubic space that will be detected by the sensor. Try increase them and see the results?

ankitdhall commented 6 years ago

[1] During the experiments, the markers were being detected up to a distance of 2m. That being said, maybe with larger marker sizes, the detection range increases; you could check that in the ArUco marker documentation.

[2] The difference in the values is just a coincidence, the files/values must have been altered while testing with multiple (different) cameras.

villanuevab commented 6 years ago

For [2], if in config_file.txt we set the use_camera_info_topic? to 0 (use intrinsic parameters from config_file.txt), are the parameters in the .ini file used anywhere?

karnikram commented 6 years ago

The .ini file is used only by the aruco_mapping package.