# US 11,445,190 B2 · Image encoding and decoding method and device for limiting partition condition of chroma block, 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 11,445,190 B2 - Document ID: US11445190B2 - Status: Granted - Kind: B2 - Application number: 17/554,688 - Filed: 2021-12-17 - Published: 2022-06-09 - Granted: 2022-09-13 - Earliest claimed: 2019-06-19 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Jangwon Choi; Jin Heo; Sunmi Yoo; Jungah Choi; Seung Hwan Kim - Web page: https://patentgrep.com/patent/US11445190B2 ## CPC - H04N 19/119: Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks - H04N 19/122: Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type - 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 19/96: Tree coding, e.g. quad-tree coding - H04N 19/42: characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation (H04N19/635 takes precedence) - 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 includes determining a splitting type of a current block, splitting the current block into a plurality of lower-layer blocks based on the splitting type, and decoding the lower-layer blocks. In this case, the current block may be a chroma block, and the determining the splitting type of the current block may be performed by disallowing a predetermined splitting type having a width or height of the lower-layer blocks being a predetermined value, among a plurality of splitting types. ## Claims ### Claim 1 An image decoding method performed by an image decoding apparatus, the image decoding method comprising: determining whether a predetermined splitting type is allowed for a current block; determining a splitting type of the current block, based on whether the predetermined splitting type is allowed for the current block; splitting the current block into a plurality of lower-layer blocks based on the determined splitting type of the current block; and decoding the lower-layer blocks, wherein, based on a width of a chroma block derived from the current block by the predetermined splitting type being 2, the predetermined splitting type is not allowed for the current block, wherein, based on a height of a chroma block derived from the current block by the predetermined splitting type being 2, the predetermined splitting type is allowed for the current block, and wherein, whether the predetermined splitting type is allowed for the current block is determined based on whether a number of times of splitting the current block from a quadtree leaf node is equal to or greater than a predetermined threshold value. ### Claim 2 (depends on 1) The image decoding method of claim 1, wherein the predetermined splitting type includes at least one of a vertical binary splitting type or a vertical ternary splitting type. ### Claim 3 (depends on 1) The image decoding method of claim 1, wherein, based on the predetermined splitting type being allowed for the current block, a width of the current block is greater than a predetermined first value. ### Claim 4 (depends on 3) The image decoding method of claim 3, wherein the predetermined first value is determined differently based on the predetermined splitting type. ### Claim 5 (depends on 1) The image decoding method of claim 1, wherein, based on the predetermined splitting type being determined as the splitting type of the current block, a width of each of the lower-layer blocks is equal to or greater than 4. ### Claim 6 (depends on 1) The image decoding method of claim 1, wherein a tree structure of the current block is a dual tree structure. ### Claim 7 An image encoding method performed by an image encoding apparatus, the image encoding method comprising: determining whether a predetermined splitting type is allowed for a current block; determining a splitting type of the current block, based on whether the predetermined splitting type is allowed for the current block; splitting the current block into a plurality of lower-layer blocks based on the determined splitting type of the current block; and encoding the lower-layer blocks, wherein, based on a width of a chroma block derived from the current block by the predetermined splitting type being 2, the predetermined splitting type is not allowed for the current block, wherein, based on a height of a chroma block derived from the current block by the predetermined splitting type being 2, the predetermined splitting type is allowed for the current block, and wherein, whether the predetermined splitting type is allowed for the current block is determined based on whether a number of times of splitting the current block from a quadtree leaf node is equal to or greater than a predetermined threshold value. ### Claim 8 (depends on 7) The image encoding method of claim 7, wherein the predetermined splitting type includes at least one of a vertical binary splitting type or a vertical ternary splitting type. ### Claim 9 (depends on 7) The image encoding method of claim 7, wherein, based on the predetermined splitting type being allowed for the current block, a width of the current block is greater than a predetermined first value. ### Claim 10 (depends on 9) The image encoding method of claim 9, wherein the predetermined first value is determined differently based on the predetermined splitting type. ### Claim 11 (depends on 7) The image encoding method of claim 7, wherein, based on the predetermined splitting type being determined as the splitting type of the current block, a width of each of the lower-layer blocks is equal to or greater than 4. ### Claim 12 (depends on 7) The image encoding method of claim 7, wherein a tree structure of the current block is a dual tree structure. ### Claim 13 A method of transmitting a bitstream generated by an image encoding method, the image encoding method comprising: determining whether a predetermined splitting type is allowed for a current block; determining a splitting type of the current block, based on whether the predetermined splitting type is allowed for the current block; splitting the current block into a plurality of lower-layer blocks based on the determined splitting type of the current block; and encoding the lower-layer blocks into the bitstream, wherein, based on a width of a chroma block derived from the current block by the predetermined splitting type being 2, the predetermined splitting type is not allowed for the current block, wherein, based on a height of a chroma block derived from the current block by the predetermined splitting type being 2, the predetermined splitting type is allowed for the current block, and wherein, whether the predetermined splitting type is allowed for the current block is determine d base d on whether a number of times of splitting the current block from a quadtree leaf node is equal to or greater than a predetermined threshold value.