1. A motion vector estimator for reducing film judder, which measures a motion vector of a block of an image comprised of blocks of pixels arranged in a matrix form, the estimator comprising: a motion vector selection device having a plurality of motion vector selectors to receive a plurality of motion vectors respectively, each motion vector selector generating N candidate vectors based on its motion vector received, and selecting the N candidate vectors of a motion vector selector to output based on a motion estimation stage signal, where N is a positive integer; N block matchmakers connected to the motion vector selection device for performing a block matching on the N candidate vectors to generate N matching costs respectively; and a motion vector determinator connected to the N block matchmakers and the motion vector selection device for determining an output motion vector of the block based on the N matching costs and feeding the output motion vector back to the motion vector selection device.