# US 10,873,761 B2 · Method, apparatus and system for encoding and decoding a subset of transform units of encoded video data > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,761 B2 - Document ID: US10873761B2 - Status: Granted - Kind: B2 - Application number: 14/394,065 - Filed: 2013-04-12 - Published: 2015-03-19 - Granted: 2020-12-22 - Earliest claimed: 2012-04-13 - Assignees: Canon Kabushiki Kaisha - Applicants: Volodymyr Kolesnikov - Inventors: Volodymyr Kolesnikov - Web page: https://patentgrep.com/patent/US10873761B2 ## CPC - H04N 19/60: using transform coding - H03M 7/4075: {Golomb codes} - H04N 19/124: Quantisation - H04N 19/13: Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] - H04N 19/14: Coding unit complexity, e.g. amount of activity or edge presence estimation (H04N19/146 takes precedence) - H04N 19/18: the unit being a set of transform coefficients - H04N 19/61: in combination with predictive coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) ## Abstract A method of decoding a transform unit (e.g., 400) of encoded video data using Golomb-Rice decoding is disclosed. Significant residual coefficients for a sub-set of the transform unit are determined A predetermined Rice parameter for Golomb-Rice decoding of the subset of the transform unit is selected. The predetermined Rice parameter being offset from a zero setting when the determined number of significant residual coefficients is higher than a predetermined threshold. The subset of the transform unit is decoded using the predetermined Rice parameter as an initial parameter for the Golomb-Rice decoding. ## Claims ### Claim 1 A decoding method for decoding a subset of a plurality of sub-sets of a transform unit of encoded video data using a Golomb-Rice method, the decoding method comprising: determining, in a unit of the subset of the plurality of sub-sets of the transform unit, an initial value of a Rice parameter for decoding a current subset of the plurality of sub-sets of the transform unit, using statistics of previously decoded residual coefficient values for a previous sub-set of the plurality of sub-sets of the transform unit, each of the subsets comprising a plurality of residual coefficient values being arranged as an array of four residual coefficient values by four residual coefficient values, wherein the transform unit is a unit for transform between a frequency-domain and a spatial-domain, and the transform unit is scanned on a subset-by-subset basis; performing initialization which initializes, in a unit of the subset of the plurality of sub-sets of the transform unit, the Rice parameter to the determined initial value; and decoding the current subset of the plurality of sub-sets of the transform unit using the Golomb-Rice method, wherein the initialized Rice parameter is used as an initial Rice parameter for decoding the current subset, and wherein a modified Rice parameter, modified from the initialized Rice parameter by using a method different from the initialization, is used as a Rice parameter for decoding the current subset, wherein the method for modification uses a last coeff abs level remaining which is a remaining absolute value of a coefficient level that is coded with Golomb-Rice code. ### Claim 2 (depends on 1) The decoding method according to the claim 1, wherein the initialized Rice parameter is determined from information decoded for the transform unit prior to decoding of the current sub-set. ### Claim 3 (depends on 2) The decoding method according to the claim 2, wherein the initialized Rice parameter is offset from a zero setting when a quantization parameter is lower than a predetermined threshold. ### Claim 4 (depends on 1) The decoding method according to the claim 1, wherein the initialized Rice parameter is determined from information decoded for the current subset of the transform unit. ### Claim 5 (depends on 4) The decoding method according to the claim 4, wherein the initialized Rice parameter is offset from a zero setting when a number of significant residual coefficient values in the current subset is higher than a predetermined threshold. ### Claim 6 An apparatus for decoding a subset of a plurality of sub-sets of a transform unit of encoded video data using a Golomb-Rice method, the apparatus comprising: a determining unit configured to determine an initial value of a Rice parameter for decoding a current subset of the plurality of sub-sets of the transform unit, using statistics of previously decoded residual coefficient values for a previous sub-set of the plurality of sub-sets of the transform unit, each of the subsets comprising a plurality of residual coefficient values being arranged as an array of four residual coefficient values by four residual coefficient values, wherein the transform unit is a unit for transform between a frequency-domain and a spatial-domain, and the transform unit is scanned on a subset-by-subset basis; an initialization unit configured to initialize the Rice parameter to the determined initial value; and a decoding unit configured to decode the current subset of the plurality of sub-sets of the transform unit using the Golomb-Rice method, wherein the initialized Rice parameter is used as an initial Rice parameter for decoding the current subset, and wherein a modified Rice parameter, modified from the initialized Rice parameter by using a method different from the initialization, is used as a Rice parameter for decoding the current subset, wherein the method for modification uses a last coeff_abs_level_remaining which is a remaining absolute value of a coefficient level that is coded with Golomb-Rice code. ### Claim 7 A system for decoding a subset of a plurality of sub-sets of a transform unit of encoded video data using a Golomb-Rice method, the system comprising: a memory for storing data and a computer program; a processor coupled to said memory for executing said computer program, said computer program comprising code for: determining, in a unit of the subset of the plurality of sub-sets of the transform unit, an initial value of a Rice parameter for decoding a current subset of the plurality of sub-sets of the transform unit, using statistics of previously decoded residual coefficient values for a previous sub-set of the plurality of sub-sets of the transform unit, each of the subsets comprising a plurality of residual coefficient values being arranged as an array of four residual coefficient values by four residual coefficient values, wherein the transform unit is a unit for transform between a frequency-domain and a spatial-domain, and the transform unit is scanned on a subset-by-subset basis; and performing initialization which initializes, in a unit of the subset of the plurality of sub-sets of the transform unit, the Rice parameter to the determined initial value; and decoding the current subset of the plurality of sub-sets of the transform unit using the Golomb-Rice method, wherein the initialized Rice parameter is used as an initial Rice parameter for decoding the current subset, and wherein a modified Rice parameter, modified from the initialized Rice parameter by using a method different from the initialization, is used as a Rice parameter for decoding the current subset, wherein the method for modification uses a last coeff abs level remaining which is a remaining absolute value of a coefficient level that is coded with Golomb-Rice code. ### Claim 8 A non-transitory computer readable medium having a computer program recorded thereon for decoding a subset of a plurality of sub-sets of a transform unit of encoded video data using a Golomb-Rice method, the program comprising: code for determining, in a unit of the subset of the plurality of sub-sets of the transform unit, an initial value of a Rice parameter for decoding a current subset of the plurality of sub-sets of the transform unit, using statistics of previously decoded residual coefficient values for a previous sub-set of the plurality of sub-sets of the transform unit, each of the subsets comprising a plurality of residual coefficient values being arranged as an array of four residual coefficient values by four residual coefficient values, wherein the transform unit is a unit for transform between a frequency-domain and a spatial-domain, and the transform unit is scanned on a subset-by-subset basis; code for performing initialization which initializes, in a unit of the subset of the plurality of sub-sets of the transform unit, the Rice parameter to the determined initial value; and code for decoding the current subset of the plurality of sub-sets of the transform unit using the Golomb-Rice method, wherein the initialized Rice parameter is used as an initial Rice parameter for decoding the current subset, and wherein a modified Rice parameter, modified from the initialized Rice parameter by using a method different from the initialization, is used as a Rice parameter for decoding the current subset, wherein the method for modification uses a last coeff abs level remaining which is a remaining absolute value of a coefficient level that is coded with Golomb-Rice code. ### Claim 9 An encoding method for encoding a subset of a plurality of sub-sets of a transform unit of video data using a Golomb-Rice method, the encoding method comprising: determining, in a unit of the subset of the plurality of sub-sets of the transform unit, an initial value of a Rice parameter for encoding a current subset of the plurality of sub-sets of the transform unit, using statistics of previously encoded residual coefficient values for a previous sub-set of the plurality of sub-sets of the transform unit, each of the subsets comprising a plurality of residual coefficient values being arranged as an array of four residual coefficient values by four residual coefficient values, wherein the transform unit is a unit for transform between a frequency-domain and a spatial-domain, and the transform unit is scanned on a subset-by-subset basis; performing initialization which initializes, in a unit of the subset of the plurality of sub-sets of the transform unit, the Rice parameter to the determined initial value; and encoding the current subset of the plurality of sub-sets of the transform unit using the Golomb-Rice method, wherein the initialized Rice parameter is used as an initial Rice parameter for encoding the current subset, and wherein a modified Rice parameter, modified from the initialized Rice parameter by using a method different from the initialization, is used as a Rice parameter for encoding the current subset, wherein the method for modification uses a last coeff abs level remaining which is a remaining absolute value of a coefficient level that is coded with Golomb-Rice code. ### Claim 10 An apparatus for encoding a subset of a plurality of sub-sets of a transform unit of video data using a Golomb-Rice method, the apparatus comprising: a determining unit configured to determine, in a unit of the subset of the plurality of sub-sets of the transform unit, an initial value of a Rice parameter for encoding a current subset of the plurality of sub-sets of the transform unit, using statistics of previously encoded residual coefficient values for a previous sub-set of the plurality of sub-sets of the transform unit, each of the subsets comprising a plurality of residual coefficient values being arranged as an array of four residual coefficient values by four residual coefficient values, wherein the transform unit is a unit for transform between a frequency-domain and a spatial-domain, and the transform unit is scanned on a subset-by-subset basis; an initialization unit configured to perform initialization which initializes, in a unit of the subset of the plurality of sub-sets of the transform unit, the Rice parameter to the determined initial value; and an encoding unit configured to encode the current subset of the plurality of sub-sets of the transform unit using the Golomb-Rice method, wherein the initialized Rice parameter is used as an initial Rice parameter for encoding the current subset, and wherein a modified Rice parameter, modified from the initialized Rice parameter by using a method different from the initialization, is used as a Rice parameter for encoding the current subset, wherein the method for modification uses a last coeff abs level remaining which is a remaining absolute value of a coefficient level that is coded with Golomb-Rice code. ### Claim 11 A system for encoding a subset of a plurality of sub-sets of a transform unit of video data using a Golomb-Rice method, the system comprising: a memory for storing data and a computer program; a processor coupled to said memory for executing said computer program, said computer program comprising code for: determining, in a unit of the subset of the plurality of sub-sets of the transform unit, an initial value of a Rice parameter for encoding a current subset of the plurality of sub-sets of the transform unit, using statistics of previously encoded residual coefficient values for a previous sub-set of the plurality of sub-sets of the transform unit, each of the subsets comprising a plurality of residual coefficient values being arranged as an array of four residual coefficient values by four residual coefficient values, wherein the transform unit is a unit for transform between a frequency-domain and a spatial-domain, and the transform unit is scanned on a subset-by-subset basis; and performing initialization which initializes, in a unit of the subset of the plurality of sub-sets of the transform unit, the Rice parameter to the determined initial value; and encoding the current subset of the plurality of sub-sets of the transform unit using the Golomb-Rice method, wherein the initialized Rice parameter is used as an initial Rice parameter for encoding the current subset, and wherein a modified Rice parameter, modified from the initialized Rice parameter by using a method different from the initialization, is used as a Rice parameter for encoding the current subset, wherein the method for modification uses a last coeff abs level remaining which is a remaining absolute value of a coefficient level that is coded with Golomb-Rice code. ### Claim 12 A non-transitory computer readable medium having a computer program recorded thereon for encoding a subset of a plurality of sub-sets of a transform unit of video data using a Golomb-Rice method, the program comprising: code for determining, in a unit of the subset of the plurality of sub-sets of the transform unit, an initial value of a Rice parameter for encoding a current subset of the plurality of sub-sets of the transform unit, using statistics of previously encoded residual coefficient values for a previous sub-set of the plurality of sub-sets of the transform unit, each of the subsets comprising a plurality of residual coefficient values being arranged as an array of four residual coefficient values by four residual coefficient values, wherein the transform unit is a unit for transform between a frequency-domain and a spatial-domain, and the transform unit is scanned on a subset-by-subset basis; code for performing initialization which initializes, in a unit of the subset of the plurality of sub-sets of the transform unit, the Rice parameter to the determined initial value; and code for encoding the current subset of the plurality of sub-sets of the transform unit using the Golomb-Rice method, wherein the initialized Rice parameter is used as an initial Rice parameter for encoding the current subset, and wherein a modified Rice parameter, modified from the initialized Rice parameter by using a method different from the initialization, is used as a Rice parameter for encoding the current subset, wherein the method for modification uses a last coeff abs level remaining which is a remaining absolute value of a coefficient level that is coded with Golomb-Rice code.