16.10. camera_calibrate

The camera_calibrate tool can generate camera models suitable for use by camera_solve and other ASP tools. This tool only solves for intrinsic camera parameters; to obtain the camera pose you should use the camera_solve tool. This tool is a wrapper around the OpenCV (http://opencv.org/) checkerboard calibration tool which takes care of converting the output into readily usable formats. When you run the tool, three camera model files will be created in the output folder: solve_cam_params.txt, vw_cam_params.tsai, and ocv_cam_params.yml. The first file can be used as a camera calibration file for the camera_solve tool. The second file is a pinhole camera format that is recognized by ASP but remember that the extrinsic parameters were not solved for so ASP is limited in what it can do with the camera file. The last file contains the camera information as formatted by the OpenCV calibration tool. If you use the first file as an input to camera_solve you must remember to replace the wildcard image path in the file with the one to the images you want to use solve for (as opposed to the checkerboard images).

In order to use this tool you must provide multiple images of the same checkerboard pattern acquired with the camera you wish to calibrate. When calling the tool you must specify the number of internal square corners contained in your checkerboard pattern (width and height can be swapped) so that OpenCV knows what to look for. You must also specify an image wildcard path such as "checkers/image_.jpg". You may need to enclose this parameter in quotes so that your command line does not expand the wildcard before it is passed to the tool. If you do not provide the –box-size parameter the output calibration numbers will be unitless.


> camera_calibrate [options] <output folder> <Board Height> <Board Width> <Image Wildcard> ...

Command-line options for camera_calibrate:

-h, --help

Display this help message.


Recompute any intermediate steps already completed on disk.


Reduce the amount of program console output.

--box-size-cm <float>

The size of the checkerboard squares in centimeters.


Make a copy of the vw param file for each input camera.