MASK FOR CHANGING LIGHTNESS PROFILE OF PHOTO COPYING

摘要

PROBLEM TO BE SOLVED: To optimize the calculation of a mask for changing a lightness profile by obtaining optimized image data by the correction of photo image data induced from image information, examining an error generated during the photo recording of the image information by them and deciding a lightness mask based on the optimized image data. SOLUTION: Light beams from the light source 12 of an exposure device 10 are irradiated through the material band of a negative 21 by optical devices 14 and 16 and then along an optical axis 18. An LCD device 20 installed in front of the negative 21 and controlled by the value of a lightness matrix is provided with a darkened area 20b for leading larger light scattering so as to capture less light in the area by a lens 22. On an opposite side, an area 20a slightly darkened or not darkened at all is present. Light passing through the LCD device 20 is successively irradiated through the negative 21 and then projected onto the print paper 26 of a band 24 provided with a photosensitive material by an optical system 21.