| 摘要 |
PROBLEM TO BE SOLVED: To perform clamp correction of sufficient capability without employing an analog feedback circuit for an image signal subjected to optical black clamping. SOLUTION: For an analog image signal to which a black level is imparted at an AGC+S/H circuit 101, A/D conversion is performed under such a state as one bit for correction is added by an A/D converter 102 thus generating digital image data 113 of N+1 bit (2<SP>n+1</SP>). A correction value generating section 103 calculates a correction value 114 by taking account of an offset level for a value obtained by correcting random noise, interchannel level difference and frame difference using the black level. An operating unit 104 subtracts the correction value 114 from the digital image data 113 to obtain N bit output data 115. COPYRIGHT: (C)2008,JPO&INPIT
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