| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a shading correction coefficient calculation method and shading correction coefficient calculation device that can correctly calculate a shading correction coefficient under a plurality of light sources different in a spectral luminance characteristic.SOLUTION: A shading correction coefficient calculation method according to the present invention is a shading correction coefficient calculation method in an imaging device converting an image formed by an imaging lens into an electric signal by an image pickup element, and the shading correction coefficient calculation method is configured to: photograph, by an imaging device, a luminance box uniform in luminance; calculate a center coordinate where a pixel value is maximum in a luminance box image having the luminance box photographed; sequentially illuminate a white chart, which is a white-colored reflection plate, by a plurality of light sources different in a spectral luminance characteristic; photograph, by the imaging device, the white chart illuminated by the light source; calculate an approximate curve surface of a pixel value from a chart image having the white chart photographed; extract a light fall-off curve surface showing a peripheral light fall-off centering around the center coordinate from the approximate curve surface; and calculate a correction coefficient for a shading correction from the light fall-off curve surface.</p> |
