Reflectance and Light Source Position Estimation from a Sparse Set of Images

In this paper, we present a new method to estimate the surface reflectance property of an object, as well as the position of a light source. The proposed method allows spatial variation in the diffuse reflectance while assuming that the specular reflectance remains constant. Given a 3D geometric model of an object with specular reflection and a small set of images from a single view as input, our method simultaneously recovers the reflectance property and the light source position by using an iterative separating-fitting technique. We estimate the light source position by firstly fitting the reflectance property to the Lambertian model and then fitting the reflectance property to a more complex reflection model while separating the specular and diffuse components iteratively. By estimating the object´s reflectance property and the light source position, we can freely render the object under arbitrary lighting conditions. Experimental results show the accuracy of our estimation method.