Method and apparatus for estimating motion vector using plurality of motion vector predictors, encoder, decoder, and decoding method

A decoding method comprising:

• performing entropy-decoding for obtaining a residual block, information on motion vector difference, and partition information from an encoded bitstream;
• selecting at least one of partitions among a plurality of candidate partitions around a current block and a candidate partition located in a position in a reference picture that spatially corresponds to the position of the current block, based on the partition information indicating the at least one of partitions, estimating a motion vector of the current block based on a motion vector of the selected at least one of partitions, and adding the decoded motion vector difference to the estimated motion vector of the current block in order to reconstruct the motion vector of the current block;
• and
• reconstructing the current block from the decoded residual block using the reconstructed motion vector,
• wherein the plurality of candidate partitions around the current block are located in a left side or an upper side of the current block.