Determining shape and reflectance properties objects by using diffuse illumination

Abstract

We propose a technique to estimate reflectance properties and the recovery of shape by using the Sample sphere and Diffuse Illumination Method. The Photometric Stereo Method (PSM) is generally based on a direct light source. Our PSM is modified with diffuse illumination and then applied to a hybrid reflectance model which consists of two main components, Lambertian and specular reflectance. A sample sphere made of one material is used to estimate the reflectance properties by using the LMS algorithm. We make a reference table which consists of surface normal and brightness values using estimated reflectance parameters. The photometric matching method proposed is robust because it matches object images with the reference table considering the neighbor brightness distribution. The 3-D shape of an object can be recovered from pixel intensity distribution and a reference table. The algorithm should be applicable to vision inspection systems.