# US 2019/0320167 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 2019/0320167 A1 - Document ID: US20190320167A1 - Status: Published application - Kind: A1 - Application number: 16/387,007 - Filed: 2019-04-17 - Published: 2019-10-17 - Earliest claimed: 2018-04-17 - Assignees: Panasonic Intellectual Property Corporation of America - Applicants: Panasonic Intellectual Property Corporation of America - Inventors: Kiyofumi ABE; Takahiro NISHI; Tadamasa TOMA; Ryuichi KANOH - Web page: https://patentgrep.com/patent/US20190320167A1 ## CPC - H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction - H04N 19/139: Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability - H04N 19/154: Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion (use of rate-distortion criteria H04N19/147) - H04N 19/167: Position within a video image, e.g. region of interest [ROI] - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/196: being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters (processing of motion vectors H04N19/513) - H04N 19/436: using parallelised computational arrangements - H04N 19/521: {for estimating the reliability of the determined motion vectors or motion vector field, e.g. for smoothing the motion vector field or for correcting motion vectors} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An encoder includes circuitry and memory. Using the memory, the circuitry: generates a prediction image to be used to encode a current block to be processed; derives a luminance correction parameter by referring to an image region which is included in an image including the current block and is outside the current block; and corrects the prediction image to be used to encode the current block, using the luminance correction parameter. The luminance correction parameter is used in common between a plurality of blocks included in the image, ## Claims ### Claim 1 An encoder, comprising: circuitry; and memory, wherein, using the memory, the circuitry: generates a prediction image to be used to encode a current block to be processed; derives a luminance correction parameter by referring to an image region which is included in an image including the current block and is outside the current block; and corrects the prediction image to be used to encode the current block, using the luminance correction parameter, and the luminance correction parameter is used in common between a plurality of blocks included in the image. ### Claim 2 (depends on 1) The encoder according to claim 1, wherein the circuitry: derives the luminance correction parameter by referring to the image region which is located around a current coding tree unit to be processed, the current coding tree unit including the plurality of blocks including the current block; and for each of the plurality of blocks included in the current coding tree unit, corrects a prediction image to be used to encode the block using the luminance correction parameter. ### Claim 3 (depends on 2) The encoder according to claim 2, wherein the image region is a region in a neighboring coding tree unit located above the current coding tree unit. ### Claim 4 (depends on 3) The encoder according to claim 3, wherein, when the neighboring coding tree unit located above the current coding tree unit is a coding tree unit which immediately precedes the current coding tree unit in processing order, the circuitry encodes each of the plurality of blocks without correcting the prediction image to be used to encode the block. ### Claim 5 (depends on 1) The encoder according to claim 1, wherein the circuitry: when the current block is located at an upper end of a current coding tree unit including the current block, derives the luminance correction parameter for the current block by referring to the image region which is in a neighboring current coding tree unit located above the current coding tree unit; when the current block is not located at the upper end of the current coding tree unit, derives a luminance correction parameter derived for a processed block located around the current block in the image as the luminance correction parameter for the current block; and corrects the prediction image to be used to encode the current block using the luminance correction parameter for the current block. ### Claim 6 (depends on 5) The encoder according to claim 5, wherein the processed block is a processed block located at a predetermined position relative to the current block. ### Claim 7 (depends on 5) The encoder according to claim 5, wherein the processed block is a most forward processed block for which a prediction image has been corrected using a luminance correction parameter in predetermined order, among a plurality of processed blocks located around the current block in the image. ### Claim 8 (depends on 5) The encoder according to claim 5, wherein the processed block is a processed block which is specified by a merge index used to derive a motion vector for the current block. ### Claim 9 (depends on 5) The encoder according to claim 5, wherein, when the neighboring coding tree unit located above the current coding tree unit is a coding tree unit which immediately precedes the current coding tree unit in processing order, the circuitry encodes the current block without correcting the prediction image for the current block. ### Claim 10 (depends on 1) The encoder according to claim 1, wherein the circuitry stores, in the memory, the luminance correction parameter derived for the current block. ### Claim 11 (depends on 1) The encoder according to claim 1, wherein the circuitry: encodes the image by a pipeline structure including, as two different stages, a correction stage in which the prediction image is corrected using the luminance correction parameter and a reconstruction stage in which a reconstructed image is generated; and delays input of a reconstructed image of the current block into the correction stage for another block located after the current block in processing order by a period of time from an end of a process in the correction stage for the current block to an end of all processes in M stages for the current block, M being a natural number. ### Claim 12 (depends on 11) The encoder according to claim 11, wherein M is a number obtainable by subtracting 1 from the number of stages from the correction stage to the reconstruction stage including the correction stage and the reconstruction stage. ### Claim 13 A decoder, comprising: circuitry; and memory, wherein, using the memory, the circuitry: generates a prediction image to be used to decode a current block to be processed; derives a luminance correction parameter by referring to an image region which is included in an image including the current block and is outside the current block; and corrects the prediction image to be used to decode the current block, using the luminance correction parameter, and the luminance correction parameter is used in common between a plurality of blocks included in the image. ### Claim 14 (depends on 13) The decoder according to claim 13, wherein the circuitry: derives the luminance correction parameter by referring to the image region which is located around a current coding tree unit to be processed, the current coding tree unit including the plurality of blocks including the current block; and for each of the plurality of blocks included in the current coding tree unit, corrects a prediction image to be used to decode the block using the luminance correction parameter. ### Claim 15 (depends on 14) The decoder according to claim 14, wherein the image region is a region in a neighboring coding tree unit located above the current coding tree unit. ### Claim 16 (depends on 15) The decoder according to claim 15, wherein, when the neighboring coding tree unit located above the current coding tree unit is a coding tree unit which immediately precedes the current coding tree unit in processing order, the circuitry decodes each of the plurality of blocks without correcting the prediction image to be used to decode the block. ### Claim 17 (depends on 13) The decoder according to claim 13, wherein the circuitry: when the current block is located at an upper end of a current coding tree unit including the current block, derives the luminance correction parameter for the current block by referring to the image region which is in a neighboring current coding tree unit located above the current coding tree unit; when the current block is not located at the upper end of the current coding tree unit, derives a luminance correction parameter derived for a processed block located around the current block in the image as the luminance correction parameter for the current block; and corrects the prediction image to be used to decode the current block using the luminance correction parameter for the current block. ### Claim 18 (depends on 17) The decoder according to claim 17, wherein the processed block is a processed block located at a predetermined position relative to the current block. ### Claim 19 (depends on 17) The decoder according to claim 17, wherein the processed block is a most forward processed block for which a prediction image has been corrected using a luminance correction parameter in predetermined order, among a plurality of processed blocks located around the current block in the image. ### Claim 20 (depends on 17) The decoder according to claim 17, wherein the processed block is a processed block which is specified by a merge index used to derive a motion vector for the current block. ### Claim 21 (depends on 17) The decoder according to claim 17, wherein, when the neighboring coding tree unit located above the current coding tree unit is a coding tree unit which immediately precedes the current coding tree unit in processing order, the circuitry decodes the current block without correcting the prediction image for the current block. ### Claim 22 (depends on 13) The decoder according to claim 13, wherein the circuitry stores, in the memory, the luminance correction parameter derived for the current block. ### Claim 23 (depends on 13) The decoder according to claim 13, wherein the circuitry: decodes the image by a pipeline structure including, as two different stages, a correction stage in which the prediction image is corrected using the luminance correction parameter and a reconstruction stage in which a reconstructed image is generated; and delays input of a reconstructed image of the current block into the correction stage for another block located after the current block in processing order by a period of time from an end of a process in the correction stage for the current block to an end of all processes in M stages for the current block, M being a natural number. ### Claim 24 (depends on 23) The decoder according to claim 23, wherein M is a number obtainable by subtracting 1 from the number of stages from the correction stage to the reconstruction stage including the correction stage and the reconstruction stage. ### Claim 25 An encoding method, comprising: generating a prediction image to be used to encode a current block to be processed; deriving a luminance correction parameter by referring to an image region which is included in an image including the current block and is outside the current block; and correcting the prediction image to be used to encode the current block, using the luminance correction parameter, wherein the luminance correction parameter is used in common between a plurality of blocks included in the image. ### Claim 26 (depends on 25) The encoding method according to claim 25, comprising: deriving the luminance correction parameter by referring to the image region which is located around a current coding tree unit to be processed, the current coding tree unit including the plurality of blocks including the current block; and for each of the plurality of blocks included in the current coding tree unit, correcting a prediction image to be used to encode the block using the luminance correction parameter. ### Claim 27 (depends on 25) The encoding method according to claim 25, comprising: when the current block is located at an upper end of a current coding tree unit including the current block, deriving the luminance correction parameter for the current block by referring to the image region which is in a neighboring current coding tree unit located above the current coding tree unit; when the current block is not located at the upper end of the current coding tree unit, deriving a luminance correction parameter derived for a processed block located around the current block in the image as the luminance correction parameter for the current block; and correcting the prediction image to be used to encode the current block using the luminance correction parameter for the current block. ### Claim 28 A decoding method, comprising: generating a prediction image to be used to decode a current block to be processed; deriving a luminance correction parameter by referring to an image region which is included in an image including the current block and is outside the current block; and correcting the prediction image to be used to decode the current block, using the luminance correction parameter, wherein the luminance correction parameter is used in common between a plurality of blocks included in the image. ### Claim 29 (depends on 28) The decoding method according to claim 28, comprising: deriving the luminance correction parameter by referring to the image region which is located around a current coding tree unit to be processed, the current coding tree unit including the plurality of blocks including the current block; and for each of the plurality of blocks included in the current coding tree unit, correcting a prediction image to be used to decode the block using the luminance correction parameter. ### Claim 30 (depends on 28) The decoding method according to claim 28, comprising: when the current block is located at an upper end of a current coding tree unit including the current block, deriving the luminance correction parameter for the current block by referring to the image region which is in a neighboring current coding tree unit located above the current coding tree unit; when the current block is not located at the upper end of the current coding tree unit, deriving a luminance correction parameter derived for a processed block located around the current block in the image as the luminance correction parameter for the current block; and correcting the prediction image to be used to decode the current block using the luminance correction parameter for the current block.