Patent ID: 8693068

Claim:
An image reading apparatus, comprising: a reading unit that includes a plurality of photoelectric conversion elements, wherein the reading unit is configured to output reading information indicating pixel values for each pixel corresponding to each of the photoelectric conversion elements by reading a document and a reference plate; and wherein the reading unit is configured to output reference plate reading information by reading the reference plate; an extraction unit configured to set a pixel of the reference plate reading information as a notice pixel and repeatedly extract one notice pixel as a target pixel until the number of the target pixels is more than a predetermined value in response to a ratio of a pixel value of the notice pixel to an initial value being more than a predetermined range, a value of the initial value being set according to a pixel position in advance; and a generation unit configured to generate correction information, wherein, in response to the extraction unit extracting all pixels of the reference plate reading information, the generation unit is configured to generate the correction information by substituting a pixel value of the target pixel with a correction value using the initial value in the reference plate reading information, and, wherein, the generation unit is configured to, in response to the extraction unit not extracting all the pixels of the reference plate reading information, generate the correction information by one from among: substituting the pixel value of the target pixel with the correction value using the initial value and substituting a pixel value of a pixel which is not set as the notice pixel with the initial value in the reference plate reading information; and setting the pixel values of all the pixels as the initial value in the reference plate reading information.