Recovery of Shape and Body Reflectance of Specular Object by Rotating Light Source

In this paper, we present a method for recovery of shape and body reflectance of specular object from a color image sequence taken with rotating light source. The image sequence is taken with a fixed camera under a fixed light source illuminating a surface of inspected objects, while the object is rotating along the axis parallel to the camera optical axis instead of light source rotation. We derive the relationship between the body reflectance at every object surface point and the rotating angle of the object. For adapting to the specular reflectance case, we develop the algorithm to extract only body reflectance component which obeys the derived relationship for estimating surface normals and body reflectance component. As a result, the object shape and body reflectance distribution of the object surface can be recovered. For demonstrating the effectiveness of the proposed method, we show the recovered shape and body reflectance component of the specular object, such as plastic ball, painted china etc.