Improving calibration of thermal stereo cameras using heated calibration board

Calibration of stereo cameras is important for accurate 3D reconstruction. For standard color cameras there are many available tools and algorithms for accurate calibration, such as detecting corners of chessboard patterns on planar calibration boards. When viewed in thermal imagery, these chessboard patterns are difficult to detect due to uniform temperature between the white and black squares. Previous techniques involve creating a custom calibration board using multiple materials. We propose improvements to a method that does not require a custom calibration board. Our method is made more reliable by using an iterative pre-processing technique to enhance contrast and a ceramic tile backing to retain heat longer. We present results which show our calibration board retains heat to reliably detect corners for over 10 minutes; our method performs well in real calibration trials.