Simultaneous photometric invariance and shape recovery

In this paper we identify the constraints under which the generally ill-posed problem of the simultaneous recovery of surface shape and its photometric invariants can be rendered tractable. We examine the cases where a single or more images are acquired using different lighting directions with a known illuminant power spectrum. Given these conditions, we state the constraints upon which the recovery of the surface geometry and its photometric parameters can be estimated. With these constraints, we then show how the recovery process may be formulated as an optimisation one which aims to fit the reflectance models under study to the image reflectance. The approach presented here is a general one and can be applied to a family of reflectance models that are based on Fresnel reflection theory. Thus, we provide the theoretical and computational background for recovering the shape, the material index of refraction and microscopic roughness factor from multi-spectral images.

• Type: Journal
• Year: 2009
• Where: ICCV
• Authors: Cong Phuoc Huynh, Antonio Robles-Kelly
• Keywords: Computer Vision, ICCV 2009, Illuminant Power Spectrum, Microscopic Roughness Factor, Reflectance Models