Thermal non-line-of-sight imaging from specular and diffuse reflections

This paper presents a non-line-of-sight technique to estimate the position and temperature of an occluded objectfrom a camera via reflection on a wall. Because objects with heat emit far infrared light with respect to theirtemperature, positions and temperatures are estimated from reflections on a wall. A key idea is that light paths from ahidden object to the camera depend on the position of the hidden object. The position of the object is recoveredfrom the angular distribution of specular and diffuse reflection component, and the temperature of the heat source isrecovered from the estimated position and the intensity of reflection. The effectiveness of our method is evaluated byconducting real-world experiments, showing that the position and the temperature of the hidden object can berecovered from the reflection destination of the wall by using a conventional thermal camera.