| 摘要 |
PURPOSE:To easily correct a gradation conversion table by correcting a gray reference conversion curve of each color on the basis of each color input signal to a gray finish point on a final output image so that a value close to a gray finish density signal is obtained, and setting the data in the gradation conversion table. CONSTITUTION:An image of an original on an input drum 1 is color-separated by an input head 3 and input density signal ID(B)-ID(R) are outputted through a photoelectric converter 4, logarithmic converter 5, AD converter 6, and equivalent neutral density converting circuit 7. The original 2 is set previously on a digitizer 18 and the position of a specific point which is to be finished in gray on an output image is inputted to a corrector 17 and stored. The corrector 17 reads the ID signal of the specific point and corrects it so that a reference gradation curve approximates to the specific point, and data on it is set in the gradation conversion table 9. The ID signals from the circuit 7 are inputted to an exposure head 14 through a color processing circuit 8, table 9, light quantity conversion table 10, DA converter 11, and modulator 13 to form a color image on a photosensitive material 16 on an output drum 15. |
