# US 12,113,975 B2 · Image encoding/decoding method and apparatus for performing prediction on basis of reconfigured prediction mode type of leaf node, and bitstream transmission method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,975 B2 - Document ID: US12113975B2 - Status: Granted - Kind: B2 - Application number: 17/789,939 - Filed: 2020-12-31 - Published: 2023-02-16 - Granted: 2024-10-08 - Earliest claimed: 2019-12-31 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Hyeong Moon Jang; Jung Hak Nam - Web page: https://patentgrep.com/patent/US12113975B2 ## CPC - H04N 19/119: Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks - H04N 19/157: Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter - H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N 19/96: Tree coding, e.g. quad-tree coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus comprises obtaining a current block corresponding to a leaf node of a split tree structure based on a predetermined prediction mode type, resetting a prediction mode type of the current block, obtaining prediction mode information of the current block based on the reset prediction mode type, and generating a prediction block of the current block based on the prediction mode information. The resetting the prediction mode type of the current block may be performed based on at least one of a slice type or size of the current block. ## Claims ### Claim 1 An image decoding method performed by an image decoding apparatus, the image decoding method comprising: obtaining a current block corresponding to a leaf node of a split tree structure based on a predetermined prediction mode type; determining a prediction mode type of the current block as either an intra type MODE_TYPE_INTRA or the predetermined prediction mode type; obtaining prediction mode information of the current block based on the determined prediction mode type; and generating a prediction block of the current block based on the obtained prediction mode information, wherein the determination of the prediction mode type of the current block is performed based on a slice type and size of the current block. ### Claim 2 (depends on 1) The image decoding method of claim 1, wherein, based on the slice type of the current block being an I slice and at least one of a width or height of the current block being greater than 64, the prediction mode type of the current block is determined as the intra type MODE_TYPE_INTRA. ### Claim 3 (depends on 1) The image decoding method of claim 1, wherein, based on the slice type of the current block being a P or B slice, the prediction mode type of the current block is determined as the predetermined prediction mode type. ### Claim 4 (depends on 1) The image decoding method of claim 1, wherein, based on a width and height of the current block being less than or equal to 64, the prediction mode type of the current block is determined as the predetermined prediction mode type. ### Claim 5 (depends on 1) The image decoding method of claim 1, wherein, based on the determined prediction mode type being the intra type MODE_TYPE_INTRA, the prediction mode information does not comprise information on a skip mode. ### Claim 6 (depends on 5) The image decoding method of claim 5, wherein the information on the skip mode is inferred as a first value specifying that the skip mode is not applied for the current block. ### Claim 7 (depends on 1) The image decoding method of claim 1, wherein the predetermined prediction mode type is determined based on prediction mode characteristic information of a higher-layer block of the current block. ### Claim 8 (depends on 1) The image decoding method of claim 1, wherein the current block is obtained by determining a split structure based on the predetermined prediction mode type and splitting a higher-layer block of the current block based on the determined split structure. ### Claim 9 (depends on 8) The image decoding method of claim 8, wherein, based on the predetermined prediction mode type being the intra type MODE_TYPE_INTRA, the split structure is determined to be a dual tree structure. ### Claim 10 (depends on 8) The image decoding method of claim 8, wherein, based on the predetermined prediction mode type being not the intra type MODE_TYPE_INTRA, the split structure is determined to be the same structure as the split structure of the higher-layer block. ### Claim 11 An image encoding method performed by an image encoding apparatus, the image encoding method comprising: obtaining a current block corresponding to a leaf node of a split tree structure based on a predetermined prediction mode type; determining a prediction mode type of the current block as either an intra type MODE_TYPE_INTRA or the predetermined prediction mode type; and encoding prediction mode information of the current block based on the determined prediction mode type, wherein the determination of the prediction mode type of the current block is performed based on a slice type and size of the current block. ### Claim 12 (depends on 11) The image encoding method of claim 11, wherein, based on the slice type of the current block being an I slice and at least one of a width or height of the current block being greater than 64, the prediction mode type of the current block is determined as the intra type MODE_TYPE_INTRA. ### Claim 13 (depends on 11) The image encoding method of claim 11, wherein, based on the determined prediction mode type being the intra type MODE_TYPE_INTRA, the prediction mode information does not comprise information on a skip mode. ### Claim 14 A non-transitory computer-readable recording medium storing a bitstream generated by an image encoding method, the image encoding method comprising: obtaining a current block corresponding to a leaf node of a split tree structure based on a predetermined prediction mode type; determining a prediction mode type of the current block as either an intra type MODE_TYPE_INTRA or the predetermined prediction mode type; and encoding prediction mode information of the current block based on the determined prediction mode type, wherein the determination of the prediction mode type of the current block is performed based on a slice type and size of the current block. ### Claim 15 A method of transmitting a bitstream generated by an image encoding method, the image encoding method comprising: obtaining a current block corresponding to a leaf node of a split tree structure based on a predetermined prediction mode type; determining a prediction mode type of the current block as either an intra type MODE_TYPE_INTRA or the predetermined prediction mode type; and encoding prediction mode information of the current block based on the determined prediction mode type, wherein the determination of the prediction mode type of the current block is performed based on a slice type and size of the current block.