Image reading apparatus

An image reading apparatus includes a reading unit having a plurality of light receiving elements arranged in a main scanning direction and configured to read an original placed on an original platen, a moving portion configured to move the reading unit in a sub-scanning direction, an edge extractor configured to extract original edges from image data of an original pressure plate and the original read by the reading unit, a determiner configured to determine, from the original edges, an angle of an original leading edge with respect to the main scanning direction and position information of one end of the original leading edge, a controller configured to terminate a movement of the reading unit when an original trailing edge end point is extracted from the original edges, and a rotation correction unit configured to correct a rotation of the image data based on the angle and the position information.