Application:camera-calib (Camera intrinsic calibration)

1. Description

This GUI program allows users to find out the camera parameters of a camera by capturing several images of a checkerboard. The program allows online grabbing or images as well as selection of pre-recorded image files. It also shows the reprojected points, undistorted images and a 3D view of the reconstructed camera poses.

Supported image sources:

• All cameras supported by OpenCV (webcams, firewire,...)
• All cameras supported by FFmpeg (IP cameras,...)
• Video files (in any format)
• Rawlog files (an MRPT format of robotic datasets).
• The stereo Bumblebee camera, for calibration of the individual cameras one at a time.
• The intensity channel of a SwisssRanger ToF 3D camera.
• The RGB intensity and IR channels of Microsoft Kinect.

Precompiled binaries of this application can be found in the Windows packages and Linux repositories.

 

2. Video tutorial

This tutorial explains how to use camera-calib to calibrate a camera with a chessboard. The program captures the images of the pattern on the fly and finally computes the camera matrix and the distortion parameters, which can be saved to plain text files:

You'll need to print a checker-board for the calibration, for example the one available for download at this link:

• camera-calibration-checker-board_9x6_25mm.pdf - 9x6, 25mm length each
• camera-calibration-checker-board_9x7.pdf - 9x7 (higher quality, sharper borders)

Note: Under Linux, you may need to execute chmod 666 /dev/video1394* and chmod 666 /dev/raw1394 for allowing user R/W access to firewire cameras without super-user rights.

3. Snapshots

The final 3D reconstruction of the camera locations around the chessboard:

The detected checkerboard:

The undistorted images:

Grabbing images of the chessboard:

Calibrating the infrarred (IR) channel camera of a Kinect (requires MRPT 0.9.4+ and, for Windows, the libfreenect):