title: Illumination estimation via thin-plate spline interpolation.
abstract: Thin-plate spline interpolation is used to interpolate the chromaticity of the color of the incident scene illumination across a training set of images. Given the image of a scene under unknown illumination, the chromaticity of the scene illumination can be found from the interpolated function. The resulting illumination-estimation method can be used to provide color constancy under changing illumination conditions and automatic white balancing for digital cameras. A thin-plate spline interpolates over a nonuniformly sampled input space, which in this case is a training set of image thumbnails and associated illumination chromaticities. To reduce the size of the training set, incremental k medians are applied. Tests on real images demonstrate that the thin-plate spline method can estimate the color of the incident illumination quite accurately, and the proposed training set pruning significantly decreases the computation.
authors.affiliation: Simon Fraser University, Burnaby V5A-1S6, Canada. lshia@cs.sfu.ca
authors.forename: Lilong
authors.initials: L
authors.lastname: Shi
authors.forename: Weihua
authors.initials: W
authors.lastname: Xiong
authors.forename: Brian
authors.initials: B
authors.lastname: Funt