Development of a new image based BRDF measurement system using a semicircular ring

We developed a new measurement system for bidirectional reflectance distribution functions (BRDF). The system can obtain simultaneously isotropic BRDF of all scattering angles utilizing a semicircular ring and an image sensor. First, we predicted the performance of our measurement system using integrated ray tracing simulation. The light path is as follows: the light from the light source at 635 nm is reflected off the target material, and the light is reflected back at the semi-circular ring. The image sensor records the light reflected from the semicircular ring. The results show good agreement with original and simulation BRDF, but detailed analysis suggested. The system improves significantly measurement time and resolution of reflection angles. Furthermore, the system is not only more cost effective than other traditional measurement systems, but also eliminated the temporal fluctuation of the light source intensity.