# US 10,321,140 B2 · Method of video coding for chroma components > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,321,140 B2 - Document ID: US10321140B2 - Status: Granted - Kind: B2 - Application number: 15/541,802 - Filed: 2016-01-07 - Published: 2017-12-21 - Granted: 2019-06-11 - Earliest claimed: 2015-01-22 - Assignees: MediaTek Singapore Pte. Ltd. - Applicants: MediaTek Singapore Pte. Ltd. - Inventors: Xianguo Zhang; Kai Zhang; Jicheng An - Web page: https://patentgrep.com/patent/US10321140B2 ## CPC - H04N 19/186: the unit being a colour or a chrominance component - H04N 19/103: Selection of coding mode or of prediction mode - H04N 19/11: among a plurality of spatial predictive coding modes - 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 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder - 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: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method for chroma Intra prediction allowing different chroma blocks in a coding unit to use separate chroma Intra prediction modes is disclosed. The method selects chroma Intra prediction modes for a first chroma block and one or more non-first chroma blocks in a current color block, where the first chroma block and at least one non-first chroma block use separate chroma Intra prediction modes. The method may comprise determining candidate mode sets for the first chroma block and the non-first chroma blocks. The method may also comprise signaling information of the chroma Intra prediction modes selected for the first chroma block and said one or more non-first chroma blocks. Furthermore, a method of chroma Intra prediction using one or more cross-chroma linear model Intra prediction modes is disclosed for improving coding efficiency of chroma Intra prediction. ## Claims ### Claim 1 A method of video decoding for chroma components using Intra prediction, the method comprising: receiving a video bitstream for coded video data; deriving, from the video bitstream, residual data associated with multiple chroma blocks corresponding to multiple chroma components in a current color block, wherein the multiple chroma blocks in the current color block comprise a first chroma block and one or more non-first chroma blocks; determining chroma Intra prediction modes from the video bitstream for the multiple chroma blocks in the current color block, wherein the chroma Intra prediction modes include one or more cross-chroma linear model modes (LM_P modes), and each LM_P mode of the one or more LM_P modes generates, independent of luma data, chroma Intra prediction data for a chroma block; when one LM_P mode of the one or more LM_P modes is selected for a current non-first chroma block of the multiple chroma blocks, generating the chroma Intra prediction data for the current non-first chroma block based on another chroma block in the current color block according to a linear model; and applying chroma Intra prediction decoding to the residual data associated with the current non-first chroma block to reconstruct the current non-first chroma block using the chroma Intra prediction data. ### Claim 2 (depends on 1) The method of claim 1, wherein said one or more LM_P modes comprises Top+Left LM_P mode, Top-Only LM_P mode, and Left-Only LM_P mode. ### Claim 3 (depends on 1) The method of claim 1, wherein one or more syntax elements are signaled to indicate chroma Intra prediction modes selected from one or more chroma mode candidate lists for the multiple chroma blocks in the current color block, and wherein at least one chroma mode candidate list includes said one or more LM_P modes. ### Claim 4 (depends on 3) The method of claim 3, wherein said one or more LM_P modes are binarized with equal-length codewords in a same way as LM modes in the one or more chroma mode candidate lists for the multiple chroma blocks in the current color block, wherein said one or more chroma mode candidate lists include said one or more LM_P modes. ### Claim 5 (depends on 3) The method of claim 3, wherein when all of the multiple chroma blocks share a same chroma Intra prediction mode and an LM_P mode is selected for the multiple chroma blocks, the chroma Intra prediction data for the first chroma block is generated according to a non-LM_P mode. ### Claim 6 (depends on 5) The method of claim 5, wherein the chroma Intra prediction data for the first chroma block is generated according to Top+Left LM mode, and wherein the chroma Intra prediction data for the first chroma block is generated by using neighboring reconstructed luma data to derive linear model parameters and using the reconstructed luma data in the current color block as prediction reference. ### Claim 7 (depends on 1) The method of claim 1, wherein when one LM_P mode is selected for the current non-first chroma block, linear model parameters of the linear model are generated based on reconstructed chroma samples. ### Claim 8 (depends on 1) The method of claim 1, wherein when one LM_P mode is selected for the current non-first chroma block, one part of linear model parameters of the linear model is generated based on reconstructed chroma samples and another part of the linear model parameters of the linear model is signaled in the video bitstream. ### Claim 9 A method of video coding for chroma components using Intra prediction, the method comprising: receiving input data associated with multiple chroma blocks corresponding to multiple chroma components in a current color block, wherein the multiple chroma blocks in the current color block comprise a first chroma block and one or more non-first chroma blocks; selecting chroma Intra prediction modes for the multiple chroma blocks, wherein the chroma Intra prediction modes include one or more cross-chroma linear model modes (LM_P modes) to generate chroma Intra prediction data for a non-first chroma block based on another chroma block in the current color block according to a linear model, wherein each LM_P mode of the one or more LM_P modes generates, independent of luma data, the chroma Intra prediction data; and applying chroma Intra prediction to the multiple chroma blocks using the chroma Intra prediction modes selected. ### Claim 10 (depends on 1) The method of claim 1, wherein each LM_P mode of the one or more LM_P modes generates the chroma Intra prediction data for the chroma block without utilizing luma data as a prediction reference.