The canonical board which allots the multiple color chips where the computer reading possible information record media null spectrum reflectance ratio which records colorimetry transfer coefficient calculation manner and colorimetry image transform manner, and the colorimetry transfer coefficient calculation device and the colorimetry image conversion device,

摘要

PROBLEM TO BE SOLVED: To provide a colorimetry conversion coefficient calculation method that eliminates the need for an exclusive unit to measure a spectral characteristic of a light source, uses an image pickup system to quickly and simply estimate a light source characteristic with high accuracy at a low cost so as to convert photographed image data into colorimetry data with high accuracy and to provide a colorimetry image pickup method, that obtains colorimetry data from a conversion coefficient, a colorimetry conversion coefficient calculation device, a colorimetry image pickup device, and an information recording medium that records a program for calculating a colorimetry conversion coefficient or for colorimetry image pickup. SOLUTION: An illumination light spectral characteristic, estimated from image data resulting from picking up color charts with different spectral reflectance factors and a conversion coefficient that is used to convert image data into a colorimetry value by using an image pickup system spectral sensitivity characteristic are calculated and by using the spectral characteristic and the spectral sensitivity characteristic, colorimetry an optimum solution is obtained to express the colorimetry value.