[OPTICAL REVIEW Vol. 4, No. 3 (1997) 358-361]

Illuminant Invariant Recovery of Surface Reflectances and Estimation of Colorimetric Values from Image Signals

Noriyuki SHIMANO*

Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-osaka, Osaka, 577 Japan

(Received December 13, 1996; Accepted February 14, 1997)

Computer simulation based on the finite-dimensional linear model for computational color constancy model has been carried out to estimate colorimetric values using image signals. We estimated the colorimetric values placing a reference object with known spectral reflectance in a scene under an unknown illuminant. It was found that prior knowledge of illuminants and surfaces of objects in a scene is not required for the estimation: any set of basis vectors to express the illuminants and any set of eigen vectors obtained by principal component analysis on data set of a color chart to represent the surfaces of different objects can be applied to the estimation.

Key words : device independent color reproductions, colorimetric calibration, computational color constancy, colorimetric values, image acquisition, image recovery