# US 2019/0246131 A1 · Inter-prediction method and apparatus in image coding system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0246131 A1 - Document ID: US20190246131A1 - Status: Published application - Kind: A1 - Application number: 16/331,807 - Filed: 2017-08-31 - Published: 2019-08-08 - Earliest claimed: 2016-09-22 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Naeri PARK; Hyeongmoon JANG; Jaehyun LIM - Web page: https://patentgrep.com/patent/US20190246131A1 ## CPC - H04N 19/51: Motion estimation or motion compensation - 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 19/14: Coding unit complexity, e.g. amount of activity or edge presence estimation (H04N19/146 takes precedence) - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/503: involving temporal prediction (adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109) - H04N 19/583: Motion compensation with overlapping blocks - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N 19/80: Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation (H04N19/635, H04N19/86 take precedence) - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An inter-prediction method according to the present invention comprises the steps of: deriving a first movement vector of the current block; deriving prediction samples for the current block on the basis of the first movement vector; deriving a subunit located in the current block and adjacent to the target boundary of same; deriving a first reference unit on the basis of the subunit and first movement vector; deriving a second movement vector of a neighboring block adjacent to the target boundary; deriving a second reference unit on the basis of the subunit and second movement vector; and deriving the modified prediction samples on the basis of weighted sum of the first reference unit and second reference unit. According to the present invention, by increasing the effectiveness of inter-prediction at the block boundary, amount of data required for residual data can be reduced and the overall coding efficiency can be increased. ## Claims ### Claim 1 An inter-prediction method performed by a decoding apparatus, the inter-prediction method comprising: deriving a first motion vector of a current block; deriving prediction samples for the current block based on the first motion vector; deriving a subunit located in the current block and adjacent to a target boundary of the current block; deriving a first reference unit based on the subunit and the first motion vector; deriving a second motion vector of a neighboring block adjacent to the target boundary; deriving a second reference unit based on the subunit and the second motion vector; and deriving modified prediction samples based on a weighted sum using the first reference unit and the second reference unit. ### Claim 2 (depends on 1) The inter-prediction method of claim 1, wherein the modified prediction samples are modified prediction samples for prediction samples located in the subunit among the prediction samples for the current block. ### Claim 3 (depends on 1) The inter-prediction method of claim 1, further comprising: determining whether overlapped block motion compensation (OBMC) is applied to the current block, wherein when the OBMC is applied to the current block, modified prediction samples are derived based on the first reference unit and the second reference unit, and when a width or a height of the current block exceeds a specific reference value, it is determined that the OBMC is applied to the current block. ### Claim 4 (depends on 3) The inter-prediction method of claim 3, wherein the specific reference value is signaled via a video parameter set (VPS), a sequence parameter set (SPS), a picture parameter set (PPS), or a slice header. ### Claim 5 (depends on 1) The inter-prediction method of claim 1, further comprising: receiving OBMC flag information; and determining whether OBMC is applied to the current block based on the OBMC flag information. ### Claim 6 (depends on 1) The inter-prediction method of claim 1, further comprising: determining whether OBMC is applied to the current block, wherein a first reference value is set for a width of the current block, a second reference value is set for a height of the current block, and when the width exceeds the first reference value or the height exceeds the second reference value, it is determined that OBMC is applied to the current block. ### Claim 7 (depends on 1) The inter-prediction method of claim 1, wherein the subunit has a non-square shape. ### Claim 8 (depends on 7) The inter-prediction method of claim 7, wherein the subunit has a size of 2×4, 4×2, 1×4, or 4×1. ### Claim 9 (depends on 8) The inter-prediction method of claim 8, wherein when a width or a height of the current block is equal to or smaller than 4, the subunit has a size of 2×4, 4×2, 1×4, or 4×1. ### Claim 10 (depends on 1) The inter-prediction method of claim 1, wherein when a height of the current block is equal to or smaller than a specific reference value, it is determined that OBMC is not applied to a left boundary or an upper boundary of the current block. ### Claim 11 (depends on 1) The inter-prediction method of claim 1, wherein a weighting factor applied to a reference sample in the first reference unit is greater than a weighting factor applied to a corresponding reference sample in the second reference unit. ### Claim 12 (depends on 1) The inter-prediction method of claim 1, wherein when the target boundary is a left boundary of the current block, a weighting factor for a first reference sample at an nth row from the target boundary, among reference samples in the first reference unit, is smaller than a weighting factor for a second reference sample at an (n+1)th row from the target boundary. ### Claim 13 (depends on 1) The inter-prediction method of claim 1, wherein weighting factors for reference samples in the first reference unit are derived based on a size of the current block, and a weighting factor for a specific reference sample among the reference samples in the first reference unit has a larger value when the size of the current block is smaller than a specific reference size than when the size of the current block is not smaller than the specific reference size. ### Claim 14 A decoding apparatus for inter-prediction, the decoding device comprising: an entropy decoder receiving inter-prediction information; and a predictor deriving a first motion vector of a current block based on the inter-prediction information, deriving prediction samples for the current block based on the first motion vector, deriving a subunit located in the current block and adjacent to a target boundary of the current block, deriving a first reference unit based on the subunit and the first motion vector, deriving a second motion vector of a neighboring block adjacent to the target boundary, deriving a second reference unit based on the subunit and the second motion vector, and deriving modified prediction samples based on a weighted sum of the first reference unit and the second reference unit. ### Claim 15 (depends on 14) The decoding apparatus of claim 14, wherein a weighting factor applied to a reference sample in the first reference unit is greater than a weighting factor applied to a corresponding reference sample in the second reference unit.