1. An apparatus for estimating a motion vector of a current block, the apparatus comprising: a partition selection unit which selects at least one of partitions, which are compared with the current block for obtaining a motion vector difference, from among a plurality of neighboring partitions around the current block based on spatial similarities between the current block and the plurality of neighboring partitions; and a motion vector estimation unit which estimates a motion vector of the selected partition as the motion vector of the current block and generates the motion vector difference, wherein the motion vector estimation unit transmits information on the motion vector difference and partition information for reconstruction of the motion vector of the current block.