According to an embodiment of the present invention, an image reader comprises a plurality of light receiving elements configured to receive light from an object to be read and to convert the light into image signals. The image reader further comprises means for determining a distance between the object and the plurality of light receiving elements at a plurality of different positions of the object. Moreover the image reader comprises means for selecting at least one correction process portion based at least on the distance between the object and the plurality of light receiving elements. The image reader comprises means for applying the at least one selected correction process to the image signal.