An image reading apparatus includes: plural image pickup elements which are arranged unidirectionally, each image pickup element including plural photoelectric transducers that convert reflected light from an original document into pixel signals, and a forwarding unit that serially forwards pixel signals acquired by the photoelectric transducers; a dividing unit that divides outputs of the photoelectric transducers into plural processing paths so that pixel signals acquired by photoelectric transducers located on both sides of a boundary between adjacent image pickup elements are included in the same division unit; and an interpolation unit that executes pixel interpolation, using the pixel signals acquired by the photoelectric transducers located on both sides of the boundary among the pixel signals divided by the dividing unit.