An illumination estimation device, comprising: a target object area extraction unit which extracts an object area from a multispectral image, the object area being an area, including specular reflection, of an object; a distribution characteristics estimation unit which estimates information representing a subspace that approximates a distribution of observation values in a spectral space, as distribution characteristics, the observation values being values to be recorded at respective pixels of the multispectral image, and the distribution characteristics being characteristics of a spreading manner of the observation values in the object area within the spectral space; a dimension reduction unit which selects one or more distribution characteristics to be used from among the distribution characteristics estimated by the distribution characteristics estimation unit, the number of selected distribution characteristics being equal to a reduced number of dimensions, the reduced number of dimensions being determined depending on a light environment at a time of capturing the multispectral image; and an illumination estimation unit which estimates spectral characteristics of illumination that illuminates the object based on the subspace information to be represented by the one or more distribution characteristics selected by the dimension reduction unit; and an illumination information storage unit which stores information representing parameters for use in configuring an illumination model, wherein the illumination estimation unit estimates the spectral characteristics of the illumination based on the subspace information and the illumination model configured based on the information stored in the illumination information storage unit, characterized in that the illumination estimation unit selects an illumination condition which is most analogous to the subspace information represented by the one or more distribution characteristics selected by the dimension reduction unit, from the illumination model configured based on the information stored in the illumination storage unit, and estimates the spectral characteristics of the illumination as spectral characteristics of illumination specified by the illumination condition. a target object area extraction unit which extracts an object area from a multispectral image, the object area being an area, including specular reflection, of an object; a distribution characteristics estimation unit which estimates information representing a subspace that approximates a distribution of observation values in a spectral space, as distribution characteristics, the observation values being values to be recorded at respective pixels of the multispectral image, and the distribution characteristics being characteristics of a spreading manner of the observation values in the object area within the spectral space; a dimension reduction unit which selects one or more distribution characteristics to be used from among the distribution characteristics estimated by the distribution characteristics estimation unit, the number of selected distribution characteristics being equal to a reduced number of dimensions, the reduced number of dimensions being determined depending on a light environment at a time of capturing the multispectral image; and an illumination estimation unit which estimates spectral characteristics of illumination that illuminates the object based on the subspace information to be represented by the one or more distribution characteristics selected by the dimension reduction unit; and an illumination information storage unit which stores information representing parameters for use in configuring an illumination model, wherein the illumination estimation unit estimates the spectral characteristics of the illumination based on the subspace information and the illumination model configured based on the information stored in the illumination information storage unit, characterized in that the illumination estimation unit selects an illumination condition which is most analogous to the subspace information represented by the one or more distribution characteristics selected by the dimension reduction unit, from the illumination model configured based on the information stored in the illumination storage unit, and estimates the spectral characteristics of the illumination as spectral characteristics of illumination specified by the illumination condition.