To convert a monochromatic image into a color image without causing any unnaturalness.
A color converting device 10 includes a lightness grasping section 14 which grasps lightness of monochromatic image data (a); a natural body/artificial body separating and extracting section 16 which extracts a body present in a natural field from the monochromatic image data; a natural body specifying section 18 which concretely specifies which natural body the body extracted by the natural body/artificial body separating and extracting section is; and a natural body image processing section 26. The natural image processing section allocates a predetermined correlation between a color phase and lightness to each of natural bodies specified by the natural body specifying section. Then a color phase for the natural body is determined based upon the correlation and lightness. Further, saturation for the natural body is determined from the lightness on the basis of a predetermined correlation between the saturation and lightness. Furthermore, a color of the natural body is determinend on the basis of the determined color phase, saturation, and lightness.
Satoshi Kono
Makoto Nakamura
Kurata Masatoshi
Takashi Mine
Yoshihiro Fukuhara
Sadao Muramatsu
Ryo Hashimoto