1. A temporal smoothing apparatus for synthesizing an intermediate image, comprising: a disparity vector estimator which receives a previous image and a present images and generates a previous disparity vector and a present disparity vector for every image block of a predetermined size; and a temporal smoothing unit which receives the previous and present images and the previous and present disparity vectors and generates a temporally-smoothed disparity vector, wherein the temporal smoothing unit generates a distinct temporally-smoothed disparity vector for each frame on the basis of a mean absolute difference between the previous image and the present image.