After sharing the reading field of the aforementioned

摘要

PPROBLEM TO BE SOLVED: To provide an image reading apparatus for improving unevenness of a read image caused at reading of an original due to characteristic differences between sensors. PSOLUTION: The image reader uses a plurality of sensors arranged in parallel in a scanning direction to scan an original and outputs line data subjected to photoelectric conversion by a plurality of the sensors as the read image of the original. The image reader includes a histogram statistic section, a characteristic calculation section, and a gradation conversion section as explained below. First, the histogram statistic section obtains a histogram by each sensor from the line data of the original. The characteristic calculation section obtains a correction processing to reduce a difference between the histograms. The gradation conversion section applies the correction processing to the line data of the read image to reduce the unevenness appearing in the read image. PCOPYRIGHT: (C)2005,JPO&NCIPI