Patent ID: 8749860

Claim:
A document reading apparatus, comprising: a conveyance portion which conveys a document; an illuminator which illuminates the document that is being conveyed by the conveyance portion; a reading portion which reads, at a read position, the document that is being conveyed by the conveyance portion; a reference member arranged opposite to the read position; a shading correction portion which performs a shading correction on image data output from the reading portion using a shading correction condition corresponding to a pixel position in a main scanning direction of the image data; a fluctuation correction portion which corrects the image data corrected by the shading correction portion using a fluctuation correction condition corresponding to the pixel position in the main scanning direction of the image data; and a fluctuation correction condition calculating portion which obtains image data output by the reading portion reading the reference member and corrected by the shading correction portion, corresponding to a predetermined pixel position in the main scanning direction and pixel positions peripheral to the predetermined pixel position in the main scanning direction, and calculates the fluctuation correction condition corresponding to the predetermined pixel position based on a fluctuation value obtained from image data, of the obtained image data, other than a first number of image data having lower brightness and a second number of image data having higher brightness and a reference value corresponding to the predetermined pixel position, wherein the second number is less than the first number.