REFLECTANCE ANALYSIS FOR 3D COMPUTER-GRAPHICS MODEL GENERATION

For synthesizing realistic images of a real three dimensional object, reflectance properties of the object surface, as well as the object sh ape, need to be measured. This paper describes one approach to create a three dimensional object model with physically correct reflectance p roperties by observing a real object. The approach consists of three s teps. First, a sequence of range images and color images is measured b y rotating a real object on a rotary table with fixed viewing and illu mination directions. Then, the object shape is obtained as a collectio n of triangular patches by merging multiple range images. Second, by u sing the recovered object shape, color pixel intensities of the color image sequence are mapped to the object surface and separated into the diffuse and specular reflection components. Finally, the separated re flection components are used to estimate parameters of the Lambertian reflection model and a simplified Torrance-Sparrow reflection model. W e have successfully tested our approach using images of a real object. Synthesized images of the object under arbitrary illumination conditi ons are shown in this paper. (C) 1996 Academic Press, Inc.