| 摘要 |
PROBLEM TO BE SOLVED: To provide an image luminosity converting device with which an image to be inputted can be automatically made proper into desirable lightness by providing maximum contrast while keeping high-fidelity colors even when its concentration is dispersed every time. SOLUTION: The luminosity of image and the attribute value of color tone are separated from the RGB signals of respective picture elements, and the luminosity distribution of luminosity signal is converted. This luminosity conversion is performed from a conversion table 15a for luminosity conversion calculated from a histogram expressing the luminosity of color image measured by prescan and the histogram of luminosity signal separated from the RGB signals. Thus, with this reconversion, the color image signal is converted from color space expressing three attributes of colors into attribute expressing luminosity and color tone, the frequency of that luminosity component for each image level is measured (141), suitable luminosity conversion is performed (143) while utilizing the feature amount of that distribution (142), and the luminosity of inputted color image can be properly changed. |
