# US 2020/0288125 A1 · Codeword assignment for intra chroma mode signalling for hevc > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0288125 A1 - Document ID: US20200288125A1 - Status: Published application - Kind: A1 - Application number: 16/883,083 - Filed: 2020-05-26 - Published: 2020-09-10 - Earliest claimed: 2011-01-14 - Assignees: Sony Corporation - Applicants: Sony Corporation - Inventors: LINA DONG; WEI LIU - Web page: https://patentgrep.com/patent/US20200288125A1 ## CPC - H04N 19/11: among a plurality of spatial predictive coding modes - 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 19/23: with coding of regions that are present throughout a whole video segment, e.g. sprites, background or mosaic - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/463: by compressing encoding parameters before transmission - H04N 19/50: using predictive coding (H04N19/61 takes precedence) - H04N 19/593: involving spatial prediction techniques - H04N 19/61: in combination with predictive coding - H04N 19/93: Run-length coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Intra prediction is used in state-of-the-art video coding standards such as AVC. The intra prediction modes are coded into the bitstream. Luma and chroma components could potentially have different prediction modes. For chroma components, there are 5 different modes defined in AVC: vertical, horizontal, DC, diagonal down right, and “same as luma”. Statistics show that the “same as luma” mode is frequent used, but in AVC, this mode is encoded using more bits than other modes during entropy coding, therefore the coding efficiency is decreased. Accordingly, a modified binarization/codeword assignment for chroma intra mode signaling is able to be utilized for high efficiency video coding (HEVC), the next generation video coding standard. ## Claims ### Claim 1 An encoding device, comprising: circuitry configured to: execute a binarization process on a same-as-luma intra prediction mode for a chroma component based on a codeword assignment for an intra prediction of the chroma component, wherein the intra prediction of the chroma component is based on a plurality of intra prediction modes for the chroma component, the plurality of intra prediction modes for the chroma component includes the same-as-luma intra prediction mode, in the same-as-luma intra prediction mode for the chroma component, an intra prediction mode for the chroma component is same as an intra prediction mode for a luma component corresponding to the chroma component, the binarization process is executed on the same-as-luma intra prediction mode such that the same-as-luma intra prediction mode is different from the plurality of intra prediction modes other than the same-as-luma intra prediction mode, the same-as-luma intra prediction mode for the chroma component is assigned to a codeword of one bit, and the one bit codeword is shorter than a plurality of codewords associated with the plurality of intra prediction modes other than the same-as-luma intra prediction mode. ### Claim 2 (depends on 1) The encoding device according to claim 1, wherein the plurality of intra prediction modes for the chroma component includes five intra prediction modes. ### Claim 3 (depends on 2) The encoding device according to claim 2, wherein the five intra prediction modes include at least one of a vertical mode, a horizontal mode, or a DC mode. ### Claim 4 (depends on 1) The encoding device according to claim 1, wherein the codeword assignment for the same-as-luma intra prediction mode is modified based on a mode value of the same-as-luma intra prediction mode. ### Claim 5 (depends on 4) The encoding device according to claim 4, wherein the circuitry is further configured to execute, based on the modified codeword assignment, an intra coding prediction process for the same-as-luma intra prediction mode. ### Claim 6 (depends on 5) The encoding device according to claim 5, wherein the circuitry is further configured to encode an image based on the execution of the intra coding prediction process. ### Claim 7 An encoding method, comprising: executing a binarization process on a same-as-luma intra prediction mode for a chroma component based on a codeword assignment for an intra prediction of the chroma component, wherein the intra prediction of the chroma component is based on a plurality of intra prediction modes for the chroma component, the plurality of intra prediction modes for the chroma component includes the same-as-luma intra prediction mode, in the same-as-luma intra prediction mode for the chroma component, an intra prediction mode for the chroma component is same as an intra prediction mode for a luma component corresponding to the chroma component, the binarization process is executed on the same-as-luma intra prediction mode such that the same-as-luma intra prediction mode is different from the plurality of intra prediction modes other than the same-as-luma intra prediction mode, the same-as-luma intra prediction mode for the chroma component is assigned to a codeword of one bit, and the one bit codeword is shorter than a plurality of codewords associated with the plurality of intra prediction modes other than the same-as-luma intra prediction mode. ### Claim 8 (depends on 7) The encoding method according to claim 7, wherein the plurality of intra prediction modes for the chroma component includes five intra prediction modes. ### Claim 9 (depends on 8) The encoding method according to claim 8, wherein the five intra prediction modes include at least one of a vertical mode, a horizontal mode, or a DC mode. ### Claim 10 (depends on 7) The encoding method according to claim 7, wherein the codeword assignment for the same-as-luma intra prediction mode is modified based on a mode value of the same-as-luma intra prediction mode. ### Claim 11 (depends on 10) The encoding method according to claim 10, further comprising executing, based on the modified codeword assignment, an intra coding prediction process for the same-as-luma intra prediction mode. ### Claim 12 (depends on 11) The encoding method according to claim 11, further comprising encoding an image based on the execution of the intra coding prediction process.