| 摘要 |
PROBLEM TO BE SOLVED: To prevent a discrimination from becoming difficult by making a part that can be discriminated from a difference in feature amounts of colors such as a hue or a saturation even if a difference of a lightness component is small in a color image, into a monochromatic image when converting color image data into monochromatic image data.SOLUTION: An image processing apparatus comprises: an input color conversion part 202 for converting color image data into Lab image data of an equal color space in which a lightness component value and a color component value are separated; a lightness/color information storage part 203 for acquiring a hue angle and lightness of a color regarding two neighboring pixels with different hue angles of colors for all pixels; a conversion parameter derivation part 204 for deriving a lightness value conversion parameter based on the acquired hue angle and lightness information; a lightness value conversion part 205 for converting the lightness component value based on the hue angles of the pixels of the Lab image data using the lightness value conversion parameter; and a monochrome image generation part 206 for generating monochrome image data based on the converted lightness component value.SELECTED DRAWING: Figure 2 |
