1. A method of tracking an object comprising: detecting predetermined object feature points in a previous frame; estimating object feature points of a present frame by using a difference between a pixel value of the previous frame and a pixel value of the present frame; estimating whether the estimated object feature points of the present frame are occluded based on a similarity between the estimated object feature points of the present frame and the detected object feature points of the previous frame, wherein the similarity is a distance between the estimated object feature points in the present frame and object features obtained by performing an affine transformation on the detected object feature points of the previous frame; and tracking the object based on the detected object feature points of the previous frame corresponding to the occluded object feature points of the present frame when the estimated object feature points of the present frame are occluded.