Abstract
This article addresses a method that predicts colorimetric values of an object under an arbitrary illuminant from an RGB image photographed by a digital still camera. When using a 3-band camera, multiple reflectance spectra that yield different colorimetric values may give the same sensor responses. This phenomenon implies that a conversion from sensor responses to accurate colorimetric values is a one-to-many relationship and cannot be uniquely determined. The proposed method can derive the colorimetric values with the highest degree of expectation from the given sensor responses by referring to the statistic feature of reflectance spectra of objects with the same material as the object to be photographed.
