📝 Automatic Targetless Lidar Camera Calibration

Auto-calibration of lidar and camera based on maximization of intensity mutual information.
This is the reimplementation of the paper: Automatic Targetless Extrinsic Calibration of a 3D Lidar and Camera by Maximizing Mutual Information

TODO

tested on Ubuntu 20.04

sudo apt-get install \
  libopencv-dev \
  libpcl-dev \
  rapidjson-dev \

make default -j`nproc`
# build examples
make apps -j`nproc`

Download livox lidar data together with images from here(If you are interested, you can search for more about low-cost livox lidars).
Extract the sample data, and create two files images.txt and point_clouds.txt that store absolute paths to image, pcd data file respectively. One line for one file.
Create camera info with camera instrinsic matrix, a sample is provided here
Create initial guess of transformation info from lidar to camera, in the form of translation(tx, ty, tz), rotation(roll, pitch, yaw); a sample is provided here
Fill absolute paths to the above files in calibration_handler_param.json

Run (after make apps)

  ./build/examples/sensors_calib_app ./data/samples/calibration_handler_param.json

After the optimization finishes, the final transformation info will be printed out.

Also the projected (image to) pointclouds; (pointcloud to) images will be saved. Check cloud.pcd and img.png files.

projected cloud:

projected cloud

projected image:

projected image