What is Camera Calibration and how good is PhotoModeler’s?

PhotoModeler includes a Camera Calibration function that determines information about your camera that improves accuracy in subsequent PhotoModeler projects. PhotoModeler calculates the camera’s focal length, lens distortion, format aspect ratio, and principal point. The resulting calibration data file can be saved on disk for use in all PhotoModeler projects that involve photos taken by that camera. Camera Calibration does not modify the camera.

High accuracy work requires a well calibrated camera. PhotoModeler’s processing and calibration algorithms have been developed and improved over a period of more than 15 years. PhotoModeler’s calibration capabilities are a match for those of any other product in the market place, even those with prices up to 25 times that of PhotoModeler. PhotoModeler’s Camera Calibrator is fully automated and very accurate, plus it is included at no extra charge as part of the basic software package. It is designed to be very easy to use and suitable for the broadest range of PhotoModeler users.

The Camera Calibrator, in it’s simplest form, uses a flat sheet or semi-flat projection of target dots. Is a flat target array the best way to do calibration? For most applications a flat sheet calibration is all you need. It is the easiest type of calibration to set up and the fastest to run. For higher accuracy, PhotoModeler has additional calibration features.

You can improve your calibration further by doing two things: a) taking the calibration photos at a distance similar to the camera / object distance in your projects, and b) using a field of 3D targets instead of a flat plane. This is easily done in PhotoModeler using the field calibration methods which are built-in features of the software that are fully described in the Help file. You can set up a project of the appropriate size and 3D shape and process in PhotoModeler like most any other project (you’ll want to take some photographs with rolled camera positions). These field calibration projects can even be fully automated if you have the Coded Targets Add-On module, provided you can print the coded targets at appropriate size. 

PhotoModeler provides the best of both worlds: a highly automated and accurate calibration method based on an easy-to-setup flat target grid that will meet most customers’ requirements, and a field calibration method for large distances and 3D fields that offers even greater accuracy for demanding applications.