A color image carrier such as positive film is brought into contact with a monochrome recording medium such as silver salt film. The color image carrier is illuminated with red, green and blue beams. These three color beams respectively can project coded information about diffraction gratings or slits which are different in angle or pitch in accordance with the respective colors. Thus, each color image carrier containing the coded information about each diffraction grating or slit is recorded on the monochrome recording medium.