Image encoding/decoding method, apparatus, and recording medium for storing bitstream

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

• deriving a Most Probable Mode (MPM) list based on intra prediction modes of neighboring blocks adjacent to a current block;
• deriving an intra prediction mode of the current block based on the MPM list;
• performing intra prediction on the current block based on the intra prediction mode;
• and
• encoding image information including information related to an intra prediction mode,
• wherein the information related to the intra prediction mode includes index information specifies one of intra prediction modes in the MPM list,
• wherein the MPM list comprises an intra prediction mode of a left block adjacent to the current block, an intra prediction mode of an upper block adjacent to the current block, and two or more additional MPM candidates,
• wherein the two or more additional MPM candidates are derived based on a minimum value and a maximum value of (i) a mode value of the intra prediction mode of the left block and (ii) a mode value of the intra prediction mode of the upper block,
• wherein the current block is divided into a plurality of sub-blocks,
• wherein an intra prediction mode for the plurality of sub-blocks is derived based on the MPM list, and
• wherein the index information is encoded based on unary binarization.

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

• obtaining a bitstream of encoded image information, wherein the encoded image information is generated based on deriving a Most Probable Mode (MPM) list based on intra prediction modes of neighboring blocks adjacent to a current block, deriving an intra prediction mode of the current block based on the MPM list, performing intra prediction on the current block based on the intra prediction mode, and encoding image information including information related to an intra prediction mode;
• and
• transmitting the image data comprising the bitstream,
• wherein the information related to the intra prediction mode includes index information specifies one of intra prediction modes in the MPM list,
• wherein the MPM list comprises an intra prediction mode of a left block adjacent to the current block, an intra prediction mode of an upper block adjacent to the current block, and two or more additional MPM candidates,
• wherein the two or more additional MPM candidates are derived based on a minimum value and a maximum value of (i) a mode value of the intra prediction mode of the left block and (ii) a mode value of the intra prediction mode of the upper block,
• wherein the current block is divided into a plurality of sub-blocks,
• wherein an intra prediction mode for the plurality of sub-blocks is derived based on the MPM list, and
• wherein the index information is encoded based on unary binarization.