Patent attributes
An object of one embodiment of the present invention is to accurately derive an inclination of a line image sensor. One embodiment of the present invention is an image reading apparatus including: a line image sensor in which reading elements for reading an image are arrayed in a predetermined direction; a first derivation unit configured to, based on read data acquired by reading a chart on which a plurality of dot patterns is printed with the line image sensor, derive coordinates of each of the plurality of dot patterns; a second derivation unit configured to derive an inclination angle of the line image sensor based on the coordinates derived by the first derivation unit; and a first calculation unit configured to calculate a first correction value for correcting the inclination of the line image sensor based on the inclination angle derived by the second derivation unit.