In accordance with one aspect of the present invention, there is provided a gaze tracking apparatus using difference image entropy, comprising: image detection module for detecting user's eye region image from image of the user taken by picture-taking apparatus which is connected to the gaze tracking apparatus; image selection module for computing entropy value of difference image between the eye region image and a plurality of reference images respectively indicating each gazing direction and selecting reference image with least difference image entropy value among the plurality of reference images; and gaze tracking module for recognizing user's gazing direction by regarding gazing direction that the selected reference image indicates as user's gazing direction.
Gaze tracking apparatus and method using difference image entropy