Recovery of shape and surface reflectance of specular object from rotation of light source

We present a method for recovery of shape and surface reflectance of specular object from color images taken with the light source rotating. The image sequence is taken with a fixed camera while the light source is relatively rotating around the axis parallel to the optical axis of the camera. We derive the relationship between the body reflectance at every object surface point and the rotating angle of the object. For the adapting specular reflectance case, we develop the algorithm to extract only the body reflectance component which obeys the derived relationship for estimating surface normals and the body reflectance component. As a result, the object shape and body reflectance distribution of the object surface can be recovered. In addition to this, reflectance parameters of specularity are also estimated by minimizing the fitting error of the specular reflectance model. For demonstrating the effectiveness of the proposed method, we show the shape, body reflectance, and specular reflectance of specular objects, which are successfully recovered by the proposed method.