# US 11,451,785 B2 · Video decoding method using simplified residual data coding in video coding system, and apparatus therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,785 B2 - Document ID: US11451785B2 - Status: Granted - Kind: B2 - Application number: 17/674,595 - Filed: 2022-02-17 - Published: 2022-06-02 - Granted: 2022-09-20 - Earliest claimed: 2019-08-31 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Jungah Choi; Jin Heo; Sunmi Yoo; Jaehyun Lim; Jangwon Choi; Seunghwan Kim - Web page: https://patentgrep.com/patent/US11451785B2 ## CPC - H04N 19/122: Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type - H04N 19/132: Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking - H04N 19/13: Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/18: the unit being a set of transform coefficients - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method for performing video decoding by a decoding device according to the present document comprises the steps of: acquiring residual information of a current block; deriving residual samples of the current block on the basis of the residual information; and generating a reconstructed picture on the basis of the residual samples. ## Claims ### Claim 1 An image decoding method, performed by a decoding apparatus, the method comprising: obtaining residual information of a current block; deriving residual samples of the current block based on the residual information; and generating a reconstructed picture based on the residual samples, wherein the obtaining the residual information comprises: obtaining syntax elements for a first transform coefficient to an n-th transform coefficient of the current block; and obtaining syntax elements for an n+1th transform coefficient to a last transform coefficient of the current block, wherein a number of context-coded syntax elements for the first transform coefficient to the n-th transform coefficient is equal to a maximum number of context coded bins of the current block, wherein the syntax elements for the first transform coefficient to the n-th transform coefficient are syntax elements according to a first residual data coding structure of Transform Skip Residual Coding (TSRC), wherein the syntax elements for the n+1th transform coefficient to the last transform coefficient are syntax elements according to a second residual data coding structure of the TSRC, and wherein the syntax elements according to the second residual data coding structure include coefficient level information and a sign flag for a transform coefficient. ### Claim 2 (depends on 1) The image decoding method of claim 1, wherein the current block is a transform skip block, wherein a transform skip flag representing whether transform is applied to the current block is obtained, and wherein a value of the transform skip flag for the current block is 1. ### Claim 3 (depends on 1) The image decoding method of claim 1, wherein the deriving the residual samples includes: deriving transform coefficients of the current block based on the syntax elements according to the first residual data coding structure and the syntax elements according to the second residual data coding structure; and deriving the residual samples based on the transform coefficients. ### Claim 4 (depends on 1) The image decoding method of claim 1, wherein the context-coded syntax elements among the syntax elements according to the first residual data coding structure includes a significant coefficient flag for whether a transform coefficient is a non-zero transform coefficient, a sign flag for a sign for the transform coefficient, a first coefficient level flag for whether a coefficient level of the transform coefficient is greater than a first threshold value, and a parity level flag for a parity of the coefficient level for the transform coefficient. ### Claim 5 (depends on 1) The image decoding method of claim 1, wherein the maximum number of the context-coded bins of the current block is derived based on a width and a height of the current block. ### Claim 6 (depends on 1) The image decoding method of claim 1, wherein the n+1th transform coefficient to the last transform coefficient are derived based on the syntax elements according to the second residual data coding structure. ### Claim 7 (depends on 6) The image decoding method of claim 6, wherein a coefficient level of the transform coefficient is derived as a value represented by the coefficient level information for the transform coefficient, and a sign of the transform coefficient is derived as a sign indicated by the sign flag. ### Claim 8 (depends on 1) The image decoding method of claim 1, wherein the context-coded bins for the current block are all used as bins of the context-coded syntax elements for the first transform coefficient to the n-th transform coefficient. ### Claim 9 An image encoding method, performed by an encoding apparatus, the method comprising: deriving residual samples for a current block; generating residual information for the residual samples; and encoding image information including the residual information, wherein the generating the residual information comprises: deriving transform coefficients for the current block based on the residual samples; generating syntax elements for a first transform coefficient to an n-th transform coefficient of the current block; and generating syntax elements for an n+1th transform coefficient to a last transform coefficient of the current block, wherein a number of context-coded syntax elements for the first transform coefficient to the n-th transform coefficient is equal to a maximum number of context coded bins of the current block, wherein the syntax elements for the first transform coefficient to the n-th transform coefficient are syntax elements according to a first residual data coding structure of Transform Skip Residual Coding (TSRC), wherein the syntax elements for the n+1th transform coefficient to the last transform coefficient are syntax elements according to a second residual data coding structure of the TSRC, and wherein the syntax elements according to the second residual data coding structure include coefficient level information and a sign flag for a transform coefficient. ### Claim 10 (depends on 9) The image encoding method of claim 9, wherein the maximum number of the context-coded bins of the current block is derived based on a width and a height of the current block. ### Claim 11 (depends on 9) The image encoding method of claim 9, wherein the current block is a transform skip block, wherein the image information includes a transform skip flag representing whether transform is applied to the current block, and wherein a value of the transform skip flag for the current block is 1. ### Claim 12 (depends on 9) The image encoding method of claim 9, wherein the context-coded bins for the current block are all used as bins of the context-coded syntax elements for the first transform coefficient to the n-th transform coefficient. ### Claim 13 (depends on 9) The image encoding method of claim 9, wherein the context-coded syntax elements among the syntax elements according to the first residual data coding structure includes a significant coefficient flag for whether a transform coefficient is a non-zero transform coefficient, a sign flag for a sign for the transform coefficient, a first coefficient level flag for whether a coefficient level of the transform coefficient is greater than a first threshold value, and a parity level flag for a parity of the coefficient level for the transform coefficient. ### Claim 14 A non-transitory computer-readable storage medium storing a bitstream generated by a method, the method comprising: deriving residual samples for a current block; generating residual information for the residual samples; encoding image information including the residual information; and generating the bitstream including the image information, wherein the generating the residual information comprises: deriving transform coefficients for the current block based on the residual samples; generating syntax elements for a first transform coefficient to an n-th transform coefficient of the current block; and generating syntax elements for an n+1th transform coefficient to a last transform coefficient of the current block, wherein a number of context-coded syntax elements for the first transform coefficient to the n-th transform coefficient is equal to a maximum number of context coded bins of the current block, wherein the syntax elements for the first transform coefficient to the n-th transform coefficient are syntax elements according to a first residual data coding structure of Transform Skip Residual Coding (TSRC), wherein the syntax elements for the n+1th transform coefficient to the last transform coefficient are syntax elements according to a second residual data coding structure of the TSRC, and wherein the syntax elements according to the second residual data coding structure include coefficient level information and a sign flag for a transform coefficient. ### Claim 15 (depends on 14) The computer-readable storage medium of claim 14, wherein the maximum number of the context-coded bins of the current block is derived based on a width and a height of the current block.