Provided is a method of using a rotational movement amount of a mobile
device including obtaining images at two different points on a path along
which the mobile device moves, searching for matching points with respect
to the obtained images and obtaining an image coordinate value of each of
the matching points, sensing linear movement of the mobile device and
obtaining a linear movement amount using a result of sensing, and
obtaining the rotational movement amount using the image coordinate
values and the linear movement amount.