An image reading apparatus is provided which allows a reading device fixed at a reading position to read images from a document while transporting the document. The apparatus includes a correcting unit adapted to perform correction processing associated with image reading performed by the reading device; a calculating unit adapted to calculate a time interval from one document to the next document that are being transported; a scheduling unit adapted to divide the correction processing into a plurality of steps and schedule the execution of the steps on the basis of the calculated time interval; and an executing unit adapted to sequentially execute the steps scheduled by the scheduling unit every time a document passes through the reading position.