This is a release of a Camera Calibration Toolbox for Matlab® with a complete documentation. This document may
also be used as a tutorial on camera calibration since it includes
general information about calibration, references and related links. Please
report bugs/questions/suggestions to Jean-Yves Bouguet at jbouguet at gmail dor com.
This toolbox works on Matlab 5.x, Matlab 6.x and Matlab 7.x on Windows, Unix
and Linux systems and does not require
any specific Matlab toolbox (for example, the optimization toolbox is not
required). Note: I have been recently informed of several GUI-related bugs on the latest Matlab release 2007b.
While fixing them, I might have introduced new ones for older versions of Matlab. Please help me maintaining this toolbox by
reporting them to me. Include in the email subject the type of the bug, and copy in the body the complete error message.
Go to the download page, and retrieve the latest version of the complete
camera calibration toolbox for Matlab.
Store the individual matlab files (.m files) into a unique
folder TOOLBOX_calib (default folder name).
and add the location of the folder TOOLBOX_calib to the main
matlab path. This procedure will let you call any of the matlab
toolbox functions from anywhere. Under Windows, this may be easily
done by using the path editing menu. Under Unix or Linux, you may use
the command path or addpath (use the help command for function description).
Run the main matlab calibration function calib_gui (or calib).
A mode selection window appears on the screen:
This selection window lets you choose between two modes of operation of the toolbox: standard or memory efficient. In standard mode, all the images used for calibration are loaded into memory once and never read again from disk. This minimizes the overall number of disk access, and speeds up all image processing and image display functions. However, if the images are large, or there are a lot of them, then the OUT OF MEMORY error message may be encountered. If this is the case, the new memory efficient version of the toolbox may be used. In this mode, every image is loaded one by one and never stored permanently in memory.
If you choose to run the standard version of the toolbox now, you can always switch to the other memory efficient mode later in case the OUT OF MEMORY error message is encountered. The two modes of operation are totally compatible (for input and output) and interchangeable.
Since both modes have the exact same user interface, in the context of this documentation, let us select the standard mode by clicking on the top button of the window. The main calibration toolbox window appears on the screen (replacing the mode selection window):
Note that the mode selection step can be bypassed altogether by directly running calib_gui(0) for the normal mode or calib_gui(1) for the memory efficient mode (try help calib_gui for more information).
You are now ready to use the toolbox for calibration.
This section takes you through a complete calibration example based on
a total of 20 (and 25) images of a planar checkerboard. This example
lets you learn how to use all the features of the toolbox: loading
calibration images, extracting image corners, running the main
calibration engine, displaying the results, controlling accuracies,
adding and suppressing images, undistorting images, exporting
calibration data to different formats... This example is highly
recommended for someone who is just starting using the toolbox.
This section shows you how to use the main calibration engine on
Zhengyou Zhang's data in a scripting mode. After going through that
example, you will also know how to change the intrinsic camera model by
choosing which parameters to optimize. This example is highly
recommended for someone who intends to use the main calibration engine
in their own matlab script files.
This example shows how to use the toolbox for calibrating a stereo system (intrinsically and extrinsically), rectifying stereo images, and performing 3D stereo triangulation. A new stereo toolbox called by stereo_gui is demonstrated.
After calibration, the list of parameters may be stored in the matlab
data file Calib_Results.mat by clicking on Save. This section
gives a detailed description of all the calibration parameters
(Intrinsic and Extrinsic) and their corresponding matlab variable
names. In addition, one to one correspondences between our notation
and Heikkilä's and Willson's notations are given.
This section contains some information regarding the initial steps of
calibration: designing the calibration rig, naming the calibration
images, image formats to use,... Very useful to get started. For the
lazy ones, a calibration pattern is even provided!