High performance grid for the metric calibration of thermographic cameras

The metric calibration of thermographic cameras would make possible the acquisition of geometric data if the principles of photogrammetry are followed. Both the distortion effects introduced in the images by the lens and the perspective effect can be corrected if the calibration parameters are known. This paper presents a calibration grid that allows the automatic metric calibration of thermographic cameras. This calibration grid is made of light and easy-to-find materials to guarantee its portability and handling. The calibration parameters obtained with the presented calibration grid are verified and compared with those obtained with a temperature-based calibration grid through the evaluation of the accuracy and repeatability in the modelling of a standard artefact previously certified. © 2012 IOP Publishing Ltd.