Design of a 3-D Infrared Imaging System Using Structured Light

Two-dimensional infrared thermography (IRT) is widely used in various domains and can be extended to more applications if the spatial information of the temperature distribution is provided to form three-dimensional (3-D) thermography. A 3-D infrared (IR) imaging system based on structured light is designed to acquire the 3-D surface temperature distribution. The projector, color camera, and IR camera must be geometrically calibrated. However, few studies have been conducted on this topic, and conventional calibration techniques cannot be directly applied to such calibration because the IR camera is sensitive only to thermal information and cannot capture visible calibration patterns. Hence, three calibration patterns are designed, and corresponding calibration methods are proposed to calibrate this system effectively and accurately. Experimental results show that this system has high spatial accuracy and can effectively obtain the temperature distribution of a 3-D surface.