OpenCV C++ Stereo Camera Calibration

A small tool for setreo camera calibration for both pinhole modle and fisheye model. this repo is modified form this repo and this repo and merge them together.

Dependencies

• OpenCV
• popt
  • if not installed, do apt-get install libpopt-dev

Compilation

Compile all the files using the following commands.

mkdir build && cd build
cmake ..
make

Make sure your are in the build folder to run the executables.

Intrinsic and extrinisics calibration of stereo camera

This can do lenses with pinhole model and fisheye model in one step. The calibration saves the camera matrix and the distortion coefficients in a YAML file. The datatype for these matrices is Mat.

Once you have compiled the sources run the following command to calibrate the intrinsics.

./calibrate_stereo [-P / -F](pinhole or fisheye)
-w [board_width_corner_number] -h [board_height_corner_number] -n [num_imgs]
-s [square_size(m)] -L [left_img_dir] -R [right_img_dir]
-l [left_img_prefix] -r [right_img_prefix] -e [extension]
(-S [scaling. Ingnore this then automatic scale]) -o [output_calib_file]

For example, the command for the test fisheye images in calib_imgs/left/ and calib_imgs/right/ with file name left1.jpg ... would be

./calibrate_stereo -F -w 8 -h 6 -n 27 -s 0.082 -L ../calib_img/left/ -R ../calib_imgs/right/ -l left -r right -o cam_stereo.yml

Undistortion and Rectification

Once you have the stereo calibration data, you can remove the distortion and rectify any pair of images so that the resultant epipolar lines become scan lines.

./undistort_rectify [-P / -F](pinhole or fisheye) -l [left_img_path]
-r [right_img_path] -c [stereo_calib_file] -L [output_left_img] -R [output_right_img]

For example

./undistort_rectify -P -l ../calib_imgs/1/left1.jpg -r ../calib_imgs/1/right1.jpg -c cam_stereo.yml -L left.jpg -R right.jpg