Image encoding/decoding method and device, and recording medium in which bitstream is stored

An image encoding method, the method comprising:

• performing a bidirectional prediction based on a first prediction mode to generate a basic prediction block of a current block;
• deriving an additional reference block of the current block based on a second prediction mode;
• and
• calculating a weighted sum of the basic prediction block and the additional reference block to generate a final prediction block of the current block.

A method for transmitting data for image information, the method comprising:

• performing a bidirectional prediction based on a first prediction mode to generate a basic prediction block of a current block;
• deriving an additional reference block of the current block based on a second prediction mode;
• calculating a weighted sum of the basic prediction block and the additional reference block to generate a final prediction block of the current block;
• encoding the current block based on the final prediction block to generate a bitstream;
• and
• transmitting data including the bitstream.