# US 12,010,299 B2 · Image encoding/decoding method and device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,010,299 B2 - Document ID: US12010299B2 - Status: Granted - Kind: B2 - Application number: 17/418,583 - Filed: 2019-12-27 - Published: 2022-03-03 - Granted: 2024-06-11 - Earliest claimed: 2018-12-27 - Assignees: Intellectual Discovery Co., Ltd. - Applicants: Intellectual Discovery Co., Ltd. - Inventors: Bae Keun Lee; Dong San Jun - Web page: https://patentgrep.com/patent/US12010299B2 ## CPC - H04N 19/11: among a plurality of spatial predictive coding modes - H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for 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: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract The video encoding/decoding method and device according to the present invention can determine an intra prediction mode of a chroma block, specify a luminance area for inter-component reference of the chroma block, downsample the specified luminance area, derive parameters for the inter-component reference of the chroma block, apply the parameters to the downsampled luminance area, and thereby predict the chroma block. ## Claims ### Claim 1 An image decoding method, comprising: determining an intra prediction mode of a chroma block; determining a neighboring region for inter-component reference of the chroma block based on the intra prediction mode, the neighboring region including at least one of a top neighboring region or a left neighboring region adjacent to a luma block corresponding to the chroma block; deriving down-sampled neighboring luma samples by down-sampling neighboring luma samples in the neighboring region, deriving a parameter for the inter-component reference of the chroma block based on the down-sampled neighboring luma samples; and predicting the chroma block based on the parameter for the inter-component reference, wherein deriving the parameter for the inter-component reference comprises: classifying the down-sampled neighboring luma samples into a first group and a second group, the first group including down-sampled neighboring luma samples having relatively large values and the second group including down-sampled neighboring luma samples having relatively small values; and calculating a maximum value by averaging the down-sampled neighboring luma samples included in the first group and a minimum value by averaging the down-sampled neighboring luma samples included in the second group, wherein the parameter for the inter-component reference is derived based on a difference between the maximum value and the minimum value, wherein when the top neighboring region belongs to a different coding tree unit from the luma block, only three neighboring luma samples are used to derive one down-sampled neighboring luma sample, and wherein when the top neighboring region belongs to a same coding tree unit as the luma block, five or six neighboring luma samples are used to derive the one down-sampled neighboring luma sample. ### Claim 2 (depends on 1) The method of claim 1, wherein the intra prediction mode of the chroma block is derived based on an index and a predetermined group configured with inter-component reference-based prediction modes, and wherein the inter-component reference-based prediction modes includes a first mode which refers to both left and top neighboring regions adjacent to the chroma block, a second mode which refers to only the left neighboring region adjacent to the chroma block and a third mode which refers to only the top neighboring region adjacent to the chroma block. ### Claim 3 (depends on 1) The method of claim 1, wherein the top neighboring region includes N sample lines and the left neighboring luma region includes M sample lines, and wherein N is set to a different value than M. ### Claim 4 (depends on 1) The method of claim 1, wherein the down-sampling is performed by using only a neighboring luma sample at a specific position and a-neighboring samples adjacent to the neighboring luma sample. ### Claim 5 (depends on 4) The method of claim 4, wherein the specific position is determined based on a position of one or more pixels selected among a plurality of samples belonging to a neighboring region of the chroma block. ### Claim 6 (depends on 5) The method of claim 5, wherein the selected one or more pixels are one or more pixels positioned at every predetermined interval in the neighboring region of the chroma block. ### Claim 7 (depends on 4) The method of claim 4, wherein the neighboring samples include a sample positioned in at least one of a left, right, top, bottom, top-left, bottom-left, top-right or bottom-right direction of the neighboring luma sample. ### Claim 8 An image encoding method, comprising: determining an intra prediction mode of a chroma block; determining a neighboring region for inter-component reference of the chroma block, the neighboring region including at least one of a top neighboring region or a left neighboring region adjacent to a luma block corresponding to the chroma block; deriving down-sampled neighboring luma samples by down-sampling neighboring luma samples in the neighboring region, deriving a parameter for the inter-component reference of the chroma block based on the down-sampled neighboring luma samples; and predicting the chroma block based on the parameter for the inter-component reference, wherein deriving the parameter for the inter-component reference comprises: classifying the down-sampled neighboring luma samples into a first group and a second group, the first group including down-sampled neighboring luma samples having relatively large values and the second group including down-sampled neighboring luma samples having relatively small values; and calculating a maximum value by averaging the down-sampled neighboring luma samples included in the first group and a minimum value by averaging the down-sampled neighboring luma samples included in the second group, wherein the parameter for the inter-component reference is derived based on a difference between the maximum value and the minimum value, wherein when the top neighboring region belongs to a different coding tree unit from the luma block, only three neighboring luma samples are used to derive one down-sample neighboring luma sample, and wherein when the top neighboring region belongs to a same coding tree unit as the luma block, five or six neighboring luma samples are used to derive the one down-sample neighboring luma sample. ### Claim 9 A non-transitory computer-readable medium storing a bitstream generated by an image encoding method, the image encoding method comprising: determining an intra prediction mode of a chroma block based on the intra prediction mode; determining a neighboring region for inter-component reference of the chroma block, the neighboring region including at least one of a top neighboring region or a left neighboring region adjacent to a luma block corresponding to the chroma block; deriving down-sampled neighboring luma samples by down-sampling neighboring luma samples in the neighboring region; deriving a parameter for the inter-component reference of the chroma block based on the down-sampled neighboring luma samples; and predicting the chroma block based on the parameter for the inter-component reference, wherein deriving the parameter for the inter-component reference comprises: classifying the down-sampled neighboring luma samples into a first group and a second group, the first group including down-sampled neighboring luma samples having relatively large values and the second group including down-sampled neighboring luma samples having relatively small values; and calculating a maximum value by averaging the down-sampled neighboring luma samples included in the first group and a minimum value by averaging the down-sampled neighboring luma samples included in the second group, wherein the parameter for the inter-component reference is derived based on a difference between the maximum value and the minimum value, wherein when the top neighboring region belongs to a different coding tree unit from the luma block, only three neighboring luma samples are used to derive one down-sample neighboring luma sample, and wherein when the top neighboring region belongs to a same coding tree unit as the luma block, five or six neighboring luma samples are used to derive the one down-sample neighboring luma sample.