Intra prediction-based image coding method and apparatus using mpm list

A video encoding method performed by an encoding apparatus, the method comprising:

• constructing candidate mode list by deriving candidate modes for a current block based on a neighboring block adjacent to a current block;
• determining an intra prediction mode for the current block;
• generating prediction samples by performing a prediction for the current block based on the intra prediction mode;
• and
• encoding image information including intra prediction mode information for the current block,
• wherein the step of determining the intra prediction mode for the current block includes:
• generating MPM (Most Probable Mode) flag information based on whether the intra prediction mode for the current block is included among the candidate modes;
• and
• generating remaining mode information for indicating the intra prediction mode for the current block among remaining intra prediction modes except the candidate modes, based on the MPM flag information representing that the intra prediction mode for the current block is not included among the candidate modes,
• wherein the MPM flag information and the remaining mode information are included and encoded in the intra prediction mode information, and
• wherein the remaining mode information is encoded based on a binarization process.

A non-transitory computer-readable storage medium storing encoded information causing a decoding apparatus to perform a video decoding method, the method comprising:

• constructing candidate mode list by deriving candidate modes for a current block based on a neighboring block adjacent to the current block;
• deriving an intra prediction mode for the current block based on the candidate mode list;
• generating predicted samples by performing prediction for the current block based on the intra prediction mode;
• and
• generating a reconstructed picture for the current block based on the predicted samples,
• wherein the step of deriving the intra prediction mode for the current block includes:
• obtaining MPM (Most Probable Mode) flag information related to whether the intra prediction mode for the current block is included among the candidate modes;
• obtaining remaining mode information for indicating the intra prediction mode for the current block among remaining intra prediction modes except for the candidate modes, based on the MPM flag information representing that the intra prediction mode for the current block is not included among the candidate modes;
• and
• deriving the intra prediction mode for the current block based on the remaining mode information,
• wherein the remaining mode information is obtained based on a binarization process.