| 摘要 |
PURPOSE:To attain effective and good accurate white balance correction by executing the white balance correction after the correction such as the color conversion and the color correction is applied to an output signal which has read a color original with an image sensor. CONSTITUTION:When a CCD chip reads the reference white plate of an original cover (now shown in the figure), the output value of respective original color signals B, G and R is controlled so that an output relative Vout of respective original colors B, G and R to input toward an input terminal Vin of a multiplying type D/A converter 141 can be mutually the same value, namely, the maximum level of an A/D converter 161 in the figure. Next, when the black part of an original 3 is read by the CCD chip, so that the black level of respective colors and the black level between respective CCD chips can be the minimum level of the A/D converter 161, the output signal of a white balance correcting part 140 is corrected by a black level correcting part 150, respective black level corrected original color signals of B, G and R are further, amplified to the dynamic range of the A/D converter 161 by a buffer amplifier 160, and continuously, converted to the digital value by the A/D converter 161.
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