Patent ID: 6954547
Filing Date: 2005-10-11
Classification: H04N

Abstract:
1. A method for deriving spectral sensitivity characteristics of a color image input device, comprising: a step of setting a constraint that tristimulus values of metamer data perceived to be the same in color by observation in a color matching evaluation experiment are made egual, to said metamer data; a step of obtaining a third objective function by assigning weights to a first objective function including a standard color matching function and to a second objective function in a uniform color space and by binding these two objective functions together; a step of obtaining, by using the method of Lagranae multipliers, a correcting color matching function used for correction to make said third objective function minimum under said constraint; a step of obtaining an amended color matching function to be amended based on a sum of said obtained correcting color matching function and said standard color matching function; and a step of obtaining spectral sensitivity characteristics amended by using said amended color matching function, wherein said metamer data includes spectral distribution data of light from an illuminant in an environment where said color matching evaluation experiment is performed, a spectral reflectance factor of a reference color stimulus used in said color matching evaluation experiment, and spectral reflectance factors of two or more color stimuli perceived to be the same in color as said reference color stimulus by observation in said color matching evaluation experiment.