bbo-calibcam 2.1.4

Calibrate intrinsic and extrinsic parameters of cameras with charuco boards

calibcam

A charuco based calibrator for camera setups (intrinsic and extrinsic coordinates).

Installation

Windows

1. (If not already done:) Install Anaconda
2. Create conda env conda env create -f https://raw.githubusercontent.com/bbo-lab/calibcam/main/environment.yml
3. Switch to calibcam environment: conda activate calibcam

Usage

Windows

1. From [repository]/boards, copy the appropriate board into the calibration video directory and rename to board.npy
2. Open Anaconda prompt via Start Menu
3. Switch to calibcam environment: conda activate calibcam
4. Run the program with python -m calibcam --videos [LIST OF VIDEOS TO INCLUDE]

BBO internal MATLAB use only:

Use MATLAB function mcl = cameralib.helper.mcl_from_calibcam([PATH TO MAT FILE OUTPUT OF CALIBRATION]) from bboanlysis_m to generate an MCL file.

Format

Result

multicam_calibration.npy/mat holds a dictionary/struct with the calibration result. The filed "calibs" holds an array of calibration dictionarys/structs with entries

* 'rvec_cam': (3,) - Rotation vector of the respective cam (world->cam)
* 'tvec_cam': (3,) - Translation vector of the respective cam (world->cam)
* 'A': (3,3) - Camera matrix
* 'k': (5,) - Camera distortion coefficients

For further structure, refer to camcalibrator.build_result()

Board

Besides the videos, each calibration folder (folder of first video) needs to contain a file board.npy. For the boards at BBO, files are available in the boards directory of the repository. Else, files must be created, containing a dict with the following entries:

* boardWidth: int - number of checkerboard squares
* boardHeight: int - number of checkerboard squares
* square_size_real: float - Absolute edge length of checkerboard squares, unit determines unit of calibration
* marker_size: float - Relative marker size
* dictionary_type: int - Aruco dictionary type

These values are used to create the board in the following way:

board = cv2.aruco.CharucoBoard_create(board_params['boardWidth'],
                                          board_params['boardHeight'],
                                          board_params['square_size_real'],
                                          board_params['marker_size'] * board_params['square_size_real'],
                                          cv2.aruco.getPredefinedDictionary( 
                                              board_params['dictionary_type']))