Motion prediction-based image coding method and device

An encoding method performed by an encoding apparatus, the encoding method comprising:

• determining a prediction mode of a current block;
• generating information on the prediction mode based on the prediction mode;
• deriving residual samples of the current block;
• deriving transform coefficients based on the residual samples;
• generating the residual information based on the transform coefficients;
• and
• encoding image information including the information on the prediction mode and the residual information,
• wherein the image information includes a sequence parameter set,
• the sequence parameter includes a combined inter-picture merge and intra-picture prediction (CIIP) enabled flag, and
• the image information includes a regular merge flag based on that a condition based on the CIIP enabled flag and a condition based on a size of the current block are satisfied.

A non-transitory computer-readable digital storage medium storing a bitstream generated by an image encoding method, the method comprising:

• determining a prediction mode of a current block;
• generating information on the prediction mode based on the prediction mode;
• deriving residual samples of the current block;
• deriving transform coefficients based on the residual samples;
• generating the residual information based on the transform coefficients;
• and
• generating the bitstream by encoding image information including the information on the prediction mode and the residual information,
• wherein the image information includes a sequence parameter set,
• the sequence parameter includes a combined inter-picture merge and intra-picture prediction (CIIP) enabled flag, and
• the image information includes a regular merge flag based on that a condition based on the CIIP enabled flag and a condition based on a size of the current block are satisfied.