Image reading apparatus, image forming apparatus, and image reading method

An image reading apparatus includes an image reading unit that includes plural photoelectric conversion elements arranged therein and that reads an image using light, the light being reflected by a document transported to a read position and being received by the plural photoelectric conversion elements, a reference plate that is disposed at the read position, a correction data generating unit that generates correction data by modifying second reference data on the basis of a ratio of first reference data to the second reference data, the first reference data being obtained by the image reading unit using light reflected by the reference plate in a clean state, the second reference data being obtained by the image reading unit using light reflected by the reference plate before reading an image, and an image correcting unit that corrects the image on the basis of the correction data generated by the correction data generating unit.