1. A frame interpolation method comprising: estimating a first motion vector by using a first frame and a second frame that follows the first frame; generating a support frame from at least either the first or the second frame by using the first motion vector; dividing the support frame into a plurality of small blocks; estimating motion vector candidates by using the first and second frames, in relation to each of the small blocks; examining a small block on the first frame, a small block on the second frame and the small blocks on the support frame, the small block on the first frame and the small block on the second frame corresponding to each of motion vector candidates; selecting a second motion vector from the motion vector candidates, the second motion vector pointing the small block on the first frame and the small block on the second frame which have the highest correlation with each of the small blocks on the support frame; and generating an interpolated frame from at least either the first or the second frame by using the second motion vector.