EasyCamCalib is a matlab software for calibrating a camera using only one image of a planar calibration grid. It is meant for cameras with lenses presenting moderate to high radial distortion (it will not work if the radial distortion is not noticeable). The software requires minimum user intervention (no need of clicking corners), and provides a reliable calibration from a single image. More images can be used for improved accuracy and robustness. Please consult the Quick Reference below, as well as the video tutorial and the users manual. In case you use the software please cite the article below where you can find a detailed explanation about the calibration algorithm.J. Barreto, J. Roquette, P. Sturm, and F. Fonseca, Automatic camera calibration applied to medical endoscopy, in Proceedings of the 20th British Machine Vision Conference, London, UK, 2009. Download EasyCamCalib v1.1 Download User Manual For more information or support contact firstname.lastname@example.org.
This tutorial video is a walktrough of the main features of the calibration toolbox. The quick reference bellow is also a good way to start using the software.
To start a calibration launch the EasyCamCalib.m script from the MATLAB prompt. This script is located at the root of the dowloaded directory.
Choose an image from the listbox by double-clicking on it. It then passes to the calibration listbox. You can add or remove images/directories using the buttons between the listboxes.
Open the options UI either using the edit menu or the option button right above the start button. In the option UI specify the grid size in millimeters and the lens type: Endoscopic/Fish-Eye Lens means that you are using a wide angle lens that projects the content into a circular area of the image and Normal Lens means that you are using a normal lens with low/moderate radial distortion.
After setting the options click on the Start button and a confirmation dialogue will appear. Double check the options and proceed.
The image will now be used to calibrate the camera. You can check the stage of the calibration process by looking at the state bar in the lower left corner. After the calibration is complete you might need to add/remove some misplaced corners. Use the Modify Points tool in the Tools menu and the image will popup so you can edit the points. The key bindings of the modify point tools are described in the User Manual.
After you are sure that no misplaced point were used in the calibration, use the Refinement menu to optimize the results using a non-linear optimizer over the reprojection error.
The calibration results are now presented as the Optimal calibration. You can check the calibration intrinsic parameters, as well as the extrinsic parameters graphical representation. You can further analyse the data as shown in the tutorial video.
Here are some other very useful calibration toolboxes publicly available: