# US 2019/0174133 A1 · Encoder, decoder, encoding method, and decoding method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174133 A1 - Document ID: US20190174133A1 - Status: Published application - Kind: A1 - Application number: 16/269,134 - Filed: 2019-02-06 - Published: 2019-06-06 - Earliest claimed: 2016-08-10 - Assignees: Panasonic Intellectual Property Corporation of America - Applicants: Panasonic Intellectual Property Corporation of America - Inventors: Kiyofumi ABE; Takashi HASHIMOTO; Takahiro NISHI; Tadamasa TOMA - Web page: https://patentgrep.com/patent/US20190174133A1 ## CPC - H04N 19/13: Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] - 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 19/18: the unit being a set of transform coefficients - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An encoder which encodes image information includes memory and circuitry accessible to the memory. The circuitry binarizes a data value indicating the number of non-zero coefficients included in a current basic block which is one of basic blocks in a frequency transform block composed of a plurality of frequency transform coefficients, according to a conversion table in which data values and binary values are associated with each other, to encode the image information which includes the data value. When binarizing the data value, the circuitry (160) selects the conversion table from tables including a first table which includes association with a data value indicating 0 as the number of non-zero coefficients and a second table which does not include association with a data value indicating 0 as the number of non-zero coefficients, and binarizes the data value according to the conversion table selected. ## Claims ### Claim 1 An encoder which encodes image information, the encoder comprising: memory; and circuitry accessible to the memory, wherein the circuitry accessible to the memory: binarizes a data value indicating the number of non-zero coefficients included in a current basic block which is one of one or more basic blocks in a frequency transform block composed of a plurality of frequency transform coefficients, according to a conversion table in which a plurality of data values and a plurality of binary values are associated with each other, to encode the image information which includes the data value; and when binarizing the data value, selects the conversion table from a plurality of tables including a first table which includes association with a data value indicating 0 as the number of non-zero coefficients and a second table which does not include association with a data value indicating 0 as the number of non-zero coefficients, and binarizes the data value according to the conversion table selected. ### Claim 2 (depends on 1) The encoder according to claim 1, wherein, when binarizing the binary value, the circuitry binarizes, as the data value indicating the number of non-zero coefficients included in a current basic block, a data value indicating the number of non-zero coefficients included in only each of a specific basic block and a following basic block in a scan order defined as a descending order of frequencies of the one or more basic blocks, the specific basic block being a basic block including a non-zero coefficient first in the one or more basic blocks. ### Claim 3 (depends on 2) The encoder according to claim 2, wherein the circuitry: when binarizing the data value, binarizes the data value only when the specific basic block is present in the one or more basic blocks; and when selecting the conversion table, selects the second table as the conversion table when the frequency transform block and the current basic block are identical. ### Claim 4 (depends on 2) The encoder according to claim 2, wherein the circuitry, when selecting the conversion table, selects the second table as the conversion table when the current basic block is the specific basic block. ### Claim 5 (depends on 1) The encoder according to claim 1, wherein the circuitry: encodes the image information, and outputs a bitstream in which the image information has been encoded; when encoding the image information and outputting the bitstream: binarizes the image information; switches whether or not to apply arithmetic encoding to a binary data string in which the image information has been binarized; when arithmetic encoding is applied to the binary data string, applies arithmetic encoding to the binary data string, and outputs the bitstream which includes the binary data string to which arithmetic encoding has been applied; and when arithmetic encoding is not applied to the binary data string, skips applying arithmetic encoding to the binary data string and outputs the bitstream which includes the binary data string to which arithmetic encoding has not been applied, and when binarizing the image information, binarizes frequency transform coefficient information which is related to frequency components of an image and included in the image information, according to different binarization formats between when arithmetic encoding is applied to the binary data string and when arithmetic encoding is not applied to the binary data string; when binarizing the image information, binarizes a part or an entirety of prediction parameter information which is related to prediction methods of an image and included in the image information, according to a common binarization format between when arithmetic encoding is applied to the binary data string and when arithmetic encoding is not applied to the binary data string; and when binarizing the frequency transform coefficient information in the case where arithmetic encoding is not applied to the binary data string, binarizes the data value included in the frequency transform coefficient information, according to the conversion table selected from the plurality of tables including the first table and the second table. ### Claim 6 A decoder which decodes image information, the decoder comprising: memory; and circuitry accessible to the memory, wherein the circuitry accessible to the memory: inverse binarizes a binary value which has been obtained by binarizing a data value according to a conversion table in which a plurality of data values and a plurality of binary values are associated with each other, to decode the image information which includes the data value, the data value indicating the number of non-zero coefficients included in a current basic block which is one of one or more basic blocks in a frequency transform block composed of a plurality of frequency transform coefficients; and when inverse binarizing the data value, selects the conversion table from a plurality of tables including a first table which includes association with a data value indicating 0 as the number of non-zero coefficients and a second table which does not include association with a data value indicating 0 as the number of non-zero coefficients, and inverse binarizes the binary value according to the conversion table selected. ### Claim 7 (depends on 6) The decoder according to claim 6, wherein, when inverse binarizing the binary value, the circuitry binarizes, as a binary value obtained by binarizing the data value indicating the number of non-zero coefficients included in a current basic block, a binary value obtained by binarizing a data value indicating the number of non-zero coefficients included in only each of a specific basic block and a following basic block in a scan order defined as a descending order of frequencies of the one or more basic blocks, the specific basic block being a basic block including a non-zero coefficient first in the one or more basic blocks. ### Claim 8 (depends on 7) The decoder according to claim 7, wherein the circuitry: when inverse binarizing the binary value, inverse binarizes the binary value only when the specific basic block is present in the one or more basic blocks; and when selecting the conversion table, selects the second table as the conversion table when the frequency transform block and the current basic block are identical. ### Claim 9 (depends on 7) The decoder according to claim 7, wherein the circuitry, when selecting the conversion table, selects the second table as the conversion table when the current basic block is the specific basic block. ### Claim 10 (depends on 6) The decoder according to claim 6, wherein the circuitry: obtains a bitstream in which the image information has been encoded, and decodes the image information; when obtaining the bitstream and decoding the image information: obtains the bitstream which includes a binary data string in which the image information has been binarized; switches whether or not to apply arithmetic decoding to the binary data string which is included in the bitstream; when arithmetic decoding is applied to the binary data string, applies arithmetic decoding to the binary data string, and inverse binarizes the binary data string to which arithmetic decoding has been applied, to decode the image information; and when arithmetic decoding is not applied to the binary data string, skips applying arithmetic decoding to the binary data string, and inverse binarizes the binary data string to which arithmetic decoding has not been applied, to decode the image information; when inverse binarizing the binary data string, inverse binarizes a first portion which is included in the binary data string and in which frequency transform coefficient information related to frequency components of an image has been binarized, according to different inverse binarization formats between when arithmetic decoding is applied to the binary data string and when arithmetic decoding is not applied to the binary data string; when inverse binarizing the binary data string, inverse binarizes a second portion which is included in the binary data string and in which a part or an entirety of prediction parameter information related to prediction methods of the image has been binarized, according to a common inverse binarization format between when arithmetic decoding is applied to the binary data string and when arithmetic decoding is not applied to the binary data string; and when inverse binarizing the first portion in the case where arithmetic decoding is not applied to the binary data string, inverse binarizes the binary value included in the first portion, according to the conversion table selected from the plurality of tables including the first table and the second table. ### Claim 11 An encoding method for encoding image information, the encoding method comprising: binarizing a data value indicating the number of non-zero coefficients included in a current basic block which is one of one or more basic blocks in a frequency transform block composed of a plurality of frequency transform coefficients, according to a conversion table in which a plurality of data values and a plurality of binary values are associated with each other, to encode the image information which includes the data value; and in the binarizing of the data value, selecting the conversion table from a plurality of tables including a first table which includes association with a data value indicating 0 as the number of non-zero coefficients and a second table which does not include association with a data value indicating 0 as the number of non-zero coefficients, and binarizing the data value according to the conversion table selected. ### Claim 12 A decoding method for decoding image information, the decoding method comprising: inverse binarizing a binary value which has been obtained by binarizing a data value according to a conversion table in which a plurality of data values and a plurality of binary values are associated with each other, to decode the image information which includes the data value, the data value indicating the number of non-zero coefficients included in a current basic block which is one of one or more basic blocks in a frequency transform block composed of a plurality of frequency transform coefficients; and in the inverse binarizing of the data value, selecting the conversion table from a plurality of tables including a first table which includes association with a data value indicating 0 as the number of non-zero coefficients and a second table which does not include association with a data value indicating 0 as the number of non-zero coefficients, and inverse binarizing the binary value according to the conversion table selected.