1. An apparatus for calculating a motion of an object, comprising: a control unit that predetermines at least one line for which first images of an object will be acquired; an image acquirement unit that acquires first images for each predetermined line for each side by performing a line scan on at least two sides of the object; an image generation unit that generates second images including the object by coupling the first images for at least one predetermined line; and a motion calculation unit that calculates motion variation of the object based on the generated second images.