| 摘要 |
PURPOSE:To correct the uneven density while applying correction to information of each unit train area, by reading out uneven density information of one unit train area and using the information read out or correcting information in response to each unit region in a rectangular region. CONSTITUTION:A rectangular area 11 on a document is read at a two-dimensional reading element CCD13 via a lens 12, an output of the CCD13 is taken as DC regeneration 16 via a capacitor 14 and an amplifier 15 and the result is given to an A/D converter 17, where the uneven density of white level is corrected at a correction circuit 21 by using a row number correcting data 20 stored in a memory 19 and a column number correcting data 18 and converts the picture signal into a digital signal of multivalued level for outputting it. In the correction of uneven density of the white level, although the correction of the memory for two-dimensional 100,000-bit is a large scale as the correction circuit, the capacity of the uneven density correction data memory is reduced remarkably by the approximate correction by means of the uneven density correcting system. |
