| 摘要 |
PROBLEM TO BE SOLVED: To provide an appropriate gradation correction without impairing an atmosphere of an image during imaging.SOLUTION: Levels of chrominance signals in non-developed imaging data are adjusted (S301), and a gamma correction is performed by determining an input lower limit value and an input upper limit value of a luminance value to be used for development on the basis of a luminance histogram (S303). In the case where a dynamic range is expanded (S306: YES), a suitable level of a gamma curve is calculated on the basis of at least either a ratio of the dynamic range at a lower luminance side than the suitable level or a ratio of the dynamic range at a higher luminance side before and after the gamma correction (S307). The gamma curve is changed using the calculated suitable level, gradation correction amounts for a dark part and a bright part in the imaging data are calculated on the basis of an eccentricity degree at the low luminance side of the luminance histogram and an eccentricity degree at the high luminance side (S308), and gradations of the dark part and the bright part are corrected with the calculated gradation correction amounts. |
