Photometric Stereo Enhanced Light Sectioning Measurement for Microtexture Road Profiling

Abstract

Existing light sectioning (LS) measurement systems are incapable of microtexture road profiling in 10 μm precision though it is needed for the analysis. This paper presents LS measurement enhanced by photometric stereo (PS) for the microtexture road profiling. Since the existing LS measurement systems, traditionally using an industrial CCD camera, suffer from the lack of not only the measurement resolution but also the camera resolution, the proposed LS measurement improves both the resolutions by implementing the PS appropriately: a DSLR camera with a macro lens is used for improving the camera resolution while the PS itself improves the measurement resolution. The surface normals derived from the PS are then incorporated through the Poisson’s integration to allow high-resolution LS measurement. The parametric study first validates the efficacy of the proposed measurement over the conventional LS measurement. Measurements on the actual road have then demonstrated the applicability of the proposed measurement to microtexture road profiling.