Image encoding/decoding method and recording medium for same

A method of encoding an image, the method comprising:

• determining multiple prediction blocks for the current block;
• and
• determining a final prediction block for the current block based on a weighted sum of the multiple prediction blocks, and
• wherein a weight of the current block for the weighted sum is derived based on a weight of a neighboring block of the current block.

A non-transitory computer readable recording medium comprising a bitstream,

• the bitstream includes:
• information about a merge index identifying respective motion information of multiple merge candidate lists, in a decoding method,
• wherein the merge index is used for deriving multiple motion information for the current block,
• wherein the multiple motion information is used to determine multiple prediction blocks for the current block,
• wherein a weighted sum of the multiple prediction blocks is used for obtaining a final prediction block of the current block, and
• wherein a weight of the current block for the weighted sum is derived based on a weight of a neighboring block of the current block.