# US 2020/0288145 A1 · Method and apparatus of palette mode coding for colour video data > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0288145 A1 - Document ID: US20200288145A1 - Status: Published application - Kind: A1 - Application number: 16/304,207 - Filed: 2017-05-26 - Published: 2020-09-10 - Earliest claimed: 2016-05-28 - Assignees: Mediatek Inc. - Applicants: Mediatek Inc. - Inventors: Tzu-Der CHUANG; Yu-Chen SUN; Shan LIU; Ching-Yeh CHEN; Yu-Wen HUANG; Xiaozhong XU; Wang-Lin LAI; Jing YE - Web page: https://patentgrep.com/patent/US20200288145A1 ## CPC - 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 19/90: using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals - H04N 19/11: among a plurality of spatial predictive coding modes - H04N 19/119: Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks - H04N 19/129: Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO] - 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: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Methods and apparatus for a coding system using palette mode coding for colour video are disclosed. According to method, when the palette mode is enabled, separate coding of luma and chroma components is disabled or if separate coding of luma and chroma components, the palette mode is disabled. According to another method, when the palette mode is enabled for the current image, palette mode coding is only applied to the luma blocks and non-palette mode coding is applied to the chroma blocks. According to yet another method, palette mode coding is applied to the luma blocks using luma palettes if the palette mode is selected for the luma blocks and palette mode coding applying to the chroma blocks using chroma palettes if the palette mode is selected for the chroma blocks. According to yet another method, the scan direction for a non-square CU depends on the shape of the non-square. ## Claims ### Claim 1 (canceled) ### Claim 2 (canceled) ### Claim 3 (canceled) ### Claim 4 (canceled) ### Claim 5 (canceled) ### Claim 6 (canceled) ### Claim 7 (canceled) ### Claim 8 (canceled) ### Claim 9 (canceled) ### Claim 10 A method of video encoding and decoding used by a video encoding system and video decoding system respectively, the method comprising: receiving input data associated with a current image, wherein the current image comprises a luma component and one or more chroma components; partitioning the luma component and said one or more chroma components of the current image separately into luma blocks and chroma blocks using separate coding unit (CU) structures; and applying palette mode coding to the luma blocks using luma palettes if the palette mode is selected for the luma blocks and applying palette mode coding to the chroma blocks using chroma palettes if the palette mode is selected for the chroma blocks. ### Claim 11 (depends on 10) The method of claim 10, wherein an initial palette predictor list is generated at a beginning of a slice, wavefront, or tiles, and wherein the initial palette predictor list is used as initial predictors for the luma blocks or chroma blocks coded in the palette mode. ### Claim 12 (depends on 11) The method of claim 11, wherein the initial palette predictor list uses a joint colour component palette, and wherein the luma blocks or chroma blocks coded in the palette mode use corresponding luma component or corresponding one or more chroma components from colour entries of the initial palette predictor list as respective palette predictors. ### Claim 13 (depends on 11) The method of claim 11, wherein the initial palette predictor list uses separate initial luma palette for the luma blocks coded in the palette mode and one or more initial chroma palettes for the chroma blocks coded in the palette mode. ### Claim 14 (depends on 13) The method of claim 13, wherein said one or more chroma components correspond to a U component and a V component, and wherein the chroma blocks for the U component and the chroma blocks for the V component either share a joint initial chroma palette or use separate initial chroma palettes. ### Claim 15 (depends on 10) The method of claim 10, wherein said one or more chroma components consist of a first chroma component and a second chroma component, each chroma palette consists of entries from the first chroma component and the second chroma component, and the chroma blocks associated with the first chroma component and the second chroma component coded in the palette mode use same chroma palettes. ### Claim 16 (depends on 10) The method of claim 10, wherein said one or more chroma components consist of a first chroma component and a second chroma component; the chroma blocks consist of first chroma blocks and second chroma blocks corresponding to the first chroma component and the second chroma component respectively; the chroma palettes consist of first chroma palettes and second chroma palettes corresponding to the first chroma component and the second chroma component respectively; and the first chroma blocks coded in the palette mode use the first chroma palettes and the second chroma blocks coded in the palette mode use the second chroma palettes. ### Claim 17 (depends on 10) The method of claim 10, wherein whether a target chroma block is coded using the palette mode is determined according to whether a collocated luma block is coded by the palette mode. ### Claim 18 (depends on 17) The method of claim 17, wherein each luma block corresponds to a luma coding unit (CU) and each chroma block corresponds to a chroma CU. ### Claim 19 (depends on 17) The method of claim 17, wherein if a top-left 4×4 block of the collocated luma block is coded by the palette mode, the target chroma block is coded by the palette mode and otherwise, the target chroma block is not coded by the palette mode. ### Claim 20 (depends on 17) The method of claim 17, wherein if any of four corner 4×4 blocks and four middle 4×4 blocks of the collocated luma block is coded by the palette mode, the target chroma block is coded by the palette mode and otherwise, the target chroma block is not coded by the palette mode. ### Claim 21 (depends on 10) The method of claim 10, wherein whether a target chroma block is coded using the palette mode is indicated by signalling in an encoder side or parsing in a decoder side a chroma palette mode syntax. ### Claim 22 (depends on 21) The method of claim 21, wherein whether the chroma palette mode syntax for the target chroma block is signalled or parsed conditionally depending on whether a collocated luma block is coded by the palette mode. ### Claim 23 (depends on 22) The method of claim 22, wherein if a top-left 4×4 block of the collocated_luma block is coded by the palette mode, the chroma palette mode syntax is signalled or parsed and otherwise the chroma palette mode syntax is not signalled or parsed; or if any of four corner 4×4 blocks and four middle 4×4 blocks of the collocated luma block is coded by the palette mode, the chroma palette mode syntax is signalled or parsed and otherwise the chroma palette mode syntax is not signalled or parsed. ### Claim 24 (depends on 22) The method of claim 22, wherein if a top-left 4×4 block of the collocated luma block is coded by the palette mode, the chroma palette mode syntax is inferred as using the palette mode and otherwise the chroma palette mode syntax is signalled or parsed; or if any of four corner 4×4 blocks and four middle 4×4 blocks of the collocated luma block is coded by the palette mode, the chroma palette mode syntax is inferred as using the palette mode and otherwise the chroma palette mode syntax is signalled or parsed. ### Claim 25 (depends on 10) The method of claim 10, wherein when a target chroma block is coded using the palette mode and a collocated luma block is also coded using the palette mode, palette scan direction of the chroma block is inherited from the palette scan direction of the collocated luma block. ### Claim 26 An apparatus of video encoding and decoding used by a video encoding system and video decoding system respectively, the apparatus comprising one or more electronic circuits or processors arrange to: receive input data associated with a current image, wherein the current image comprises a luma component and one or more chroma components; partition the luma component and said one or more chroma components of the current image separately into luma blocks and chroma blocks using separate coding unit (CU) structures; and apply palette mode coding to the luma blocks using luma palettes if the palette mode is selected for the luma blocks and apply palette mode coding to the chroma blocks using chroma palettes if the palette mode is selected for the chroma blocks. ### Claim 27 (canceled) ### Claim 28 (canceled) ### Claim 29 (canceled) ### Claim 30 (canceled) ### Claim 31 (canceled) ### Claim 32 (canceled)