Estimation of Radiometric Parameters for a Realistic Rendering of 3D Models

In order to obtain realistic results in the rendering of a 3D model, we need accurate information on both structure (shape) and radiometric properties (reflectivity) of its surfaces. In this paper, we approach the problem of correctly estimating the radiometric characteristics of an imaged surface through the analysis of several of its views. The images are acquired with one or more CCD cameras that move around the object, and the 3D model is assumed available (it can be constructed from the available images). The adopted reflectivity model is non-Lambertian as it takes into account both the diffuse lobe and the specular lobe. The method implements a robust technique which is able to estimate the reflectivity parameters of the object's surfaces even in the presence of modeling imperfections and/or when the relative camera-object position and orientation are only approximately known.