| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image reader capable of reducing the size of a storage area for reference data while performing shading correction in an appropriate time without deteriorating accuracy. <P>SOLUTION: An image reader includes: a reference data acquisition unit 51 for acquiring white reference data and black reference data to be used for shading correction as integer data; a short bit length data generation unit 52 for generating short bit length data with bit lengths respectively being shorter than those of the white reference data and black reference data; and a white reference memory 53 and a black reference memory 54 for respectively storing the data. The short bit length data generation unit 52 generates short bit length data having a value to be obtained by subtracting each offset value from each reference data value. Each offset value is set to be a predetermined value lower than a predicted minimum value of each reference data to be acquired by the reference data acquisition unit 51. <P>COPYRIGHT: (C)2013,JPO&INPIT |
