Spectral luminance distribution

Patent Granted PROBLEM TO BE SOLVED: To estimate the spectral luminance distribution of a light source with a simple configuration without using any spectrophotometers. ; SOLUTION: The image of the light source of spectral luminance distribution SL is photographed under spectral sensitivity characteristics S1. The spectral sensitivity characteristics are set to be spectral sensitivity characteristics S2 by interposing a filter, and the image of the light source is photographed under it. A pixel value at a region corresponding to the video signal of a light source is acquired from images photographed under the two different spectral sensitivity characteristics S1, S2.