A terminal device includes an acquisition unit that acquires image information of a read-out original, a display unit that displays the image information acquired by the acquisition unit, a detection unit that detects pitch information by performing frequency analysis of the image information displayed by the display unit, and a control unit that controls the image information so as to be enlarged or reduced in accordance with a size of the original and controls to display the pitch information so as to be superimposed on the image information which is enlarged or reduced.