Determination of Object Shape and Reflectance Based on Moire System Using Multiple Light Sources and a Reflection Model

摘要

A method for determining the three-dimensional shape and surface reflectance of an object from images is presented. The method is based on a combination of Moire analysis and a reflection model, and is defined for objects with reflectance formulated using Phong's reflection model. Objects are regarded as consisting of multiple surfaces, each with specific and uniform reflectance, and the number of regions is assumed to be known for simplicity. The proposed method overcomes two problems in reflectance estimation: ambiguity of reflectance due to the relationship between the surface normal and the components of diffuse and specular reflectance, and the lack of reflectance information for pixels with zero intensity due to the grating pattern employed for Moire analysis. Using multiple light sources, multiple images with shifted grating phase are captured and analyzed for Moire analysis. The method is confirmed through numerical simulations and experiments to obtain accurate shape and reflectance information, with a significant improvement over existing image-based methods.