1. A method for predicting a motion vector of a current block using a motion vector of an adjacent partition that is adjacent to the current block, the method comprising: predicting a global motion vector of the current block; calculating a first motion vector difference between a motion vector of the current block and a motion vector of the adjacent partition, and a second motion vector difference between the motion vector of the current block and the predicted global motion vector of the current block; predicting, as the motion vector of the current block, a motion vector having a minimum Rate-Distortion (RD) cost, based on the first motion vector difference and the second motion vector difference; and generating motion information related to the current block and transmitting the motion information, wherein the motion information related to the current block includes a motion vector difference between the motion vector of the current block and the predicted motion vector of the current block, a global motion vector for each frame of the current block, and information about the predicted motion vector of the current block, and wherein the predicted motion vector of the current block is a motion vector of an adjacent partition adjacent to the current block or a global motion vector of the current block.