A read sensor generates front side image information indicating an image on a front side of an object to be read, and front side measurement information indicating a line of an image in a main scanning direction on the front side of a correction chart. A read sensor generates back side image information indicating an image on a back side of the object to be read, and back side measurement information indicating a line of an image in the main scanning direction on the back side of the correction chart. The image correction device calculates an amount of misalignment of read positions based on the front side measurement information and the back side measurement information, and corrects misalignment of images on the front side and the back side of the object to be read, indicated by the front side image information and the back side image information.