Illumination Color and Intrinsic Surface Properties : Physics-based Color Analyses from a Single Image

概要

論文の詳細を見る
A consistent color descriptor of an object is a significant requirement for many applications in computer vision. In the real world, unfortunately, the color appearances of objects are generally not consistent. It depends principally on two factors: illumination spectral power distribution (illumination color) and intrinsic surface properties. Consequently, to obtain objects' consistent color descriptors, we have to deal with those two factors. The former is commonly referred to as color constancy: a capabilty to estimate and discount the illumination color, while the latter is identical to the problem of recovering body color from highlights. This recovery is crucial because high-lights emitted from opaque inhomogeneous objects can cause the surface colors to be inconsistent with regard to the change of viewing and illuminant directions. We base our color constancy methods on analyzing high-lights or specularities emitted from opaque inhomogeaeous objects. We have successfully derived a linear correlation between image chromaticity and illumination chromaticity. This linear correlation is clearly described in inverse-intensity chromaticity space. a novel two-dimensional space we introduce. Through this space, we become able to effectively estimate illumination chromaticity (illumination color) from both uniformly colored surfaces and highly textured surfaces in a single integrated framework, thereby making our method significantly advanced over the existing methods. By knowing the illumination chromaticity, we can normalize the input image such that its illumination color becomes pure white. Meanwhile, for separating reflection components, we propose an approach that is based on an iterative framework and a specular-free image. The specular-free image is an image that is free from specularities yet has different body color from the input image. In general, the approach relies principally on image intensity and color. All methods of color constancy and reflection-components separation proposed in this paper are analyzed based on physical phenomena of the real world, making the estimation more accurate, and have strong basics of analysis. In addition, all methods require only a single input image. This is not only practical, but also challenging in term of complexity.
一般社団法人情報処理学会の論文
2004-05-06

Illumination Color and Intrinsic Surface Properties : Physics-based Color Analyses from a Single Image

スポンサーリンク

概要

著者

関連論文

スポンサーリンク