| 摘要 |
PURPOSE:To remove noises generated at the formation of correcting data effectively and to obtain an excellent picture signal by connecting a memory for storing a signal obtained by reading out a reference surface and arithmetically processing the signal stored in the memory to form a corrected signal. CONSTITUTION:Prior to scanning, a reference white plate to be a reference is read out and the read-out picture is A/D converted in each line of main scanning and stored in an RAM52. The stored signal is read out synchronously with the real picture read out from the original and applied to an address signal line of an ROM54. A signal obtained by matching the timing of an input picture signal through a type flip-flop 50 is inputted to the ROM54 and the ROM54 executes the arithmetic processing for the correction of shading and stores the processed result. When the arithmetic result for the shading correction which is stored in the ROM54 is read out, a signal from which shading caused by the uneven light emitting of a fluorescent lamp as an illuminating light source, uneven density due to the dirt or the like of a reflecting mirror and the uneven distribution of luminance intensity of an optical lens is removed is obtained.
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