Determining Illuminant Position and Reflectance Properties
from a Single Image under Perspective Projection
Kenji Hara Nobuaki Inaguma Ko Nishino Katsushi Ikeuchi
We propose a new method for estimating specular reflection parameters of a real object surface from a single image, as well as the illuminant position. Polarization is used for separating the diffuse and specular reflection components. Different from previous approaches, which heavily assumed both distant viewpoint and illuminant position, our method can work even under short distance of them. Given a specular reflection component, the method begins with estimating the position of the light source. At the same time, the initial values of reflectance parameters are also estimated by linearizing the reflection model with a variable transformation. The estimated reflection parameters are then refined based on the original reflection model.
Publication
1. K. Hara, N. Inaguma, K. Nishino and K. Ikeuchi, ``Determining Reflectance Parameters from a Single Image under Perspective Projection,'' IPSJ Transactions on Computer Vision and Image Media, 2001-CVIM-130, pp.15-22, Dec., 2001 (in Japanese).
Left:Perspective projection
Right:Reflection model
Left:Polarization
Right:Illuminant position estimation
Left:Original image
Center:Synthetic image Results
Right:Error color map