# US 11,445,189 B2 · Image encoding/decoding method and device, and method for transmitting bitstream > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,189 B2 - Document ID: US11445189B2 - Status: Granted - Kind: B2 - Application number: 17/472,137 - Filed: 2021-09-10 - Published: 2022-03-10 - Granted: 2022-09-13 - Earliest claimed: 2019-03-13 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Ling Li; Jin Heo; Moonmo Koo; Jung Hak Nam - Web page: https://patentgrep.com/patent/US11445189B2 ## 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 19/186: the unit being a colour or a chrominance component - H04N 19/593: involving spatial prediction techniques - 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 according to the present disclosure may include determining whether a prediction mode of a current block is an intra prediction mode based on information on the prediction mode of the current block, determining whether intra sub-partitions (ISP) is available for the current block, when the prediction mode of the current block is an intra prediction mode, decoding an ISP application indicator indicating whether to apply ISP to the current block, when ISP is available for the current block, and generating a prediction block for the current block by applying ISP to the current block, upon determining that ISP applies to the current block based on the ISP application indicator. ## Claims ### Claim 1 An image decoding method performed by an image decoding apparatus, the image decoding method comprising: determining a prediction mode of a current block based on prediction mode information of the current block; determining whether intra sub-partitions (ISP) is available for the current block based on the prediction mode of the current block being an intra prediction mode; decoding ISP mode information for the current block, based on the ISP being available for the current block; and generating a prediction sample for the current block based on the ISP mode information, wherein the ISP mode information includes whether the current block is partitioned into sub-partitions. ### Claim 2 (depends on 1) The image decoding method of claim 1, wherein the determining whether the ISP is available for the current block is performed based on comparison between a size of a luma component block of the current block and a predetermined threshold. ### Claim 3 (depends on 2) The image decoding method of claim 2, wherein the predetermined threshold is a maximum transform size. ### Claim 4 (depends on 2) The image decoding method of claim 2, wherein, when both a width and height of the luma component block of the current block are equal to or less than a predetermined threshold, it is determined that the ISP is available for the current block. ### Claim 5 (depends on 1) The image decoding method of claim 1, wherein the generating the prediction sample for the current block based on the ISP mode information comprises: generating a prediction sample for a luma component block by applying the ISP to the luma component block of the current block; determining whether to apply the ISP to a chroma component block of the current block; and generating a prediction sample for the chroma component block by applying the ISP to the chroma component block, upon determining that the ISP applies to the chroma component block of the current block. ### Claim 6 (depends on 5) The image decoding method of claim 5, wherein the determining whether to apply the ISP to the chroma component block of the current block is performed based on at least one of a size of the chroma component block or a chroma format of the current block. ### Claim 7 (depends on 6) The image decoding method of claim 6, wherein, when the chroma format of the current block is 4:2:2 or 4:4:4 and at least one of a width or height of the chroma component block is greater than a maximum transform size, it is determined that the ISP applies to the chroma component block of the current block. ### Claim 8 (depends on 5) The image decoding method of claim 5, wherein, when the ISP applies to the chroma component block, a split direction and a number of sub-partitions for the chroma component block are determined based on a split direction and a number of sub-partitions for the luma component block. ### Claim 9 (depends on 8) The image decoding method of claim 8, wherein the split direction and the number of sub-partitions for the chroma component block are equal to the split direction and the number of sub-partitions for the luma component block, respectively. ### Claim 10 (depends on 1) The image decoding method of claim 1, wherein the generating the prediction sample for the current block based on the ISP mode information comprises: generating a prediction sample for a luma component block by applying the ISP to the luma component block of the current block; and generating a prediction sample for a chroma component block by applying the ISP to the chroma component block of the current block. ### Claim 11 (depends on 10) The image decoding method of claim 10, wherein a split direction and a number of sub-partitions for the chroma component block are determined based on a split direction and a number of sub-partitions for the luma component block. ### Claim 12 (depends on 11) The image decoding method of claim 11, wherein the split direction and the number of sub-partitions for the chroma component block are equal to the split direction and (the number of sub-partitions/2) of the luma component block, respectively. ### Claim 13 An image decoding apparatus comprising: a memory; and at least one processor, wherein the at least one processor is configured to: determine a prediction mode of a current block based on prediction mode information of the current block; determine whether intra sub-partitions (ISP) is available for the current block based on the prediction mode of the current block being an intra prediction mode; decode ISP mode information for the current block, based on the ISP being available for the current block; and generate a prediction sample for the current block based on the ISP mode information, wherein the ISP mode information includes whether the current block is partitioned into sub-partitions. ### Claim 14 An image encoding method performed by an image encoding apparatus, the image encoding method comprising: determining a prediction mode of a current block; determining whether intra sub-partitions (ISP) is available for the current block based on the prediction mode of the current block being an intra prediction mode; determining whether to apply the ISP to the current block, based on the ISP being available for the current block; generating a prediction sample for the current block by applying the ISP to the current block, based on the ISP being determined to be applied to the current block; and encoding prediction mode information of the current block and ISP mode information, wherein the ISP mode information includes whether the current block is partitioned into sub-partitions. ### Claim 15 (depends on 14) A method of transmitting a bitstream generated by the image encoding method of claim 14, comprising: transmitting the bitstream including the encoded prediction mode information and the encoded ISP mode information.