One-shot reflectance direction color mapping for identifying surface roughness

Surface roughness, an important property of products, can be identified using the bidirectional reflectance distribution function (BRDF). A method to identify surface roughness is thus proposed using a one-shot reflectance direction color mapping imaging system. This imaging system can capture BRDF information across the entire field of view in one shot. Histograms of color variations in the captured images reveal that the surfaces with different roughness values on a metal piece can be identified even at a sub -micrometer scale.