Time-Resolved Far Infrared Light Transport Decomposition for Thermal Photometric Stereo

Abstract

We present a novel time-resolved light transport decomposition method using thermal imaging. Because the speed of heat propagation is much slower than the speed of light propagation, transient transport of far infrared light can be observed at a video frame rate. A key observation is that the thermal image looks similar to the visible light image in an appropriately controlled environment. This implies that conventional computer vision techniques can be straightforwardly applied to the thermal image. We show that the diffuse component in the thermal image can be separated and, therefore, the surface normals of objects can be estimated by the Lambertian photometric stereo. The effectiveness of our method is evaluated by conducting real-world experiments, and its applicability to black body, transparent, and translucent objects is shown.

Polarimetric Light Transport Analysis for Specular Inter-Reflection

“…O'Toole et al proposed primal-dual coding [8] using a coaxial projector-camera setup, and his follow-up work uses epipolar constraints [9], [10]. Other methods decompose reflection components by far infrared light [11] or the timeof-flight approach [22].…”

“…There are numerous different techniques to decompose light transport components. These techniques use the relationship between reflection components and optical properties, such as the dichromatic reflectance model [1]- [6], spatial frequency response [7], geometric constraint [8]- [10], far infrared light [11] and polarization [12]- [18]. These different physical cues target different optical phenomena, and they complement each other.…”