| 摘要 |
PROBLEM TO BE SOLVED: To ensure gradation in a dark part when conducting processing on the image data read. SOLUTION: A preprocessing section 100 is provided with an offset-correcting circuit 102 for applying offset correction to analog image data outputted from a CCD image sensor 78 and amplified; an A/D converting circuit 103 for applying A/D conversion to the offset-corrected analog image data; a filter processing circuit 104 for selecting filter-processed data, obtained by applying spatial filtering processing to the A/D-converted digital image data and filter-unprocessed data that have not been subjected to the spatial filtering processing and outputting the selected data; and a subtracting circuit 105 for applying subtraction processing corresponding to the previously performed offset correction to the filter output data to be outputted from the circuit 104. By applying offset correction to the analog image data can be reduced, the influence of noise contained in the analog image data, and the gradation in the dark part, i.e. a high-density part can be secured. COPYRIGHT: (C)2006,JPO&NCIPI
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