An image interpolation method comprises searching a motion vector from different pairs of blocks on a first and a second reference image symmetrically, extracting a first and a second image block from the first and the second reference image, respectively, the first and the second image block being located by the motion vector, determining a region determination threshold using an absolute difference between paired opposite pixels of the first and the second image block, extracting from each of the first and the second image block a first pixel region that the absolute difference is smaller than the region determination threshold, and obtaining a pixel value of a second pixel region of the to-be-interpolated block from a pixel value of the first pixel region of each of the first and the second image block, the second pixel region corresponding to the first pixel region.