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Spectra Estimation of Fluorescent and Reflective Scenes by Using Ordinary Illuminants
Yinqiang Zheng1, Imari Sato1, and Yoichi Sato2
1National Institute of Informatics, Japan
yqzheng@nii.ac.jp
imarik@nii.ac.jp
2The University of Tokyo, Japan
ysato@iis.u-tokyo.ac.jp
Abstract. The spectrum behavior of a typical fluorescent object is regulated by its reflectance, absorption and emission spectra. It was shown that two high-frequency and complementary illuminations in the spectral domain can be used to simultaneously estimate reflectance and emission spectra. In spite of its accuracy, such specialized illuminations are not easily accessible. This motivates us to explore the feasibility of using ordinary illuminants to achieve this task with comparable accuracy. We show that three hyperspectral images under wideband and independent illuminants are both necessary and sufficient, and successfully develop a convex optimization method for solving. We also disclose the reason why using one or two images is inadequate, although embedding the linear low-dimensional models of reflectance and emission would lead to an apparently overconstrained equation system. In addition, we propose a novel four-parameter model to express absorption and emission spectra, which is more compact and discriminative than the linear model. Based on this model, we present an absorption spectra estimation method in the presence of three illuminations. The correctness and accuracy of our proposed model and methods have been verified.
Keywords: Fluorescence, reflectance, hyperspectral imaging
LNCS 8693, p. 188 ff.
lncs@springer.com
© Springer International Publishing Switzerland 2014