# US 2019/0174136 A1 · Method and apparatus for image encoding/decoding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174136 A1 - Document ID: US20190174136A1 - Status: Published application - Kind: A1 - Application number: 16/321,173 - Filed: 2017-08-09 - Published: 2019-06-06 - Earliest claimed: 2016-08-11 - Assignees: Electronics and Telecommunications Research Institute - Applicants: Electronics and Telecommunications Research Institute - Inventors: Dong San JUN; Ha Hyun LEE; Jung Won KANG; Hyun Suk KO; Sung Chang LIM; Jin Ho LEE; Seung Hyun CHO; Hui Yong KIM; Jin Soo CHOI - Web page: https://patentgrep.com/patent/US20190174136A1 ## CPC - H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction - 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 19/126: Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers - 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 19/463: by compressing encoding parameters before transmission - H04N 19/513: Processing of motion vectors - H04N 19/593: involving spatial prediction techniques - H04N 19/96: Tree coding, e.g. quad-tree coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract The present invention relates to a method for encoding/decoding a video. To this end, the method for decoding a video may include: deriving a spatial merge candidate from at least one of spatial candidate blocks of a current block, deriving a temporal merge candidate from a co-located block of the current block, and generating a prediction block of the current block based on at least one of the derived spatial merge candidate and the derived temporal merge candidate, wherein a reference picture for the temporal merge candidate is selected based on a reference picture list of a current picture including the current block and a reference picture list of a co-located picture including the co-located block. ## Claims ### Claim 1 A method for decoding a video, the method comprising: deriving a spatial merge candidate from at least one of spatial candidate blocks of a current block; deriving a temporal merge candidate from a co-located block of the current block; and generating a prediction block of the current block based on at least one of the derived spatial merge candidate and the derived temporal merge candidate, wherein a reference picture for the temporal merge candidate is selected based on a reference picture list of a current picture including the current block and a reference picture list of a co-located picture including the co-located block. ### Claim 2 (depends on 1) The method of claim 1, wherein the reference picture for the temporal merge candidate is selected based on whether the reference picture list of the current picture and the reference picture list of the co-located picture are equal to each other. ### Claim 3 (depends on 1) The method of claim 1, wherein when the reference picture list of the current picture and the reference picture list of the co-located picture are equal to each other, the reference picture for the temporal merge candidate is selected as a reference picture being used by a motion vector derived from the co-located block. ### Claim 4 (depends on 1) The method of claim 1, wherein when at least one reference picture of the reference picture list of the current picture is same as at least one reference picture of the reference picture list of the co-located picture, the reference picture for the temporal merge candidate is selected from the same at least one reference picture. ### Claim 5 (depends on 1) The method of claim 1, wherein the reference picture for the temporal merge candidate is selected according to an inter prediction direction. ### Claim 6 (depends on 1) The method of claim 1, wherein the spatial merge candidate and the temporal merge candidate of the current block are derived for each sub-block of the current block. ### Claim 7 (depends on 6) The method of claim 6, wherein the temporal merge candidate of the sub-block of the current block is derived from a sub-block at a same position as a sub-block of the current block included in the co-located block. ### Claim 8 (depends on 7) The method of claim 7, wherein when the sub-block at the same position is unavailable, the temporal merge candidate of the sub-block of the current block is derived from one of a sub-block of a center position in the co-located block, a left sub-block of the sub-block at the same position, and a top sub-block of the sub-block at the same position. ### Claim 9 (depends on 1) The method of claim 1, wherein the deriving of the temporal merge candidate includes: scaling a plurality of motion vectors of the co-located block based on respective reference pictures of a reference picture list of the current block, and deriving the temporal merge candidate including the scaled plurality of motion vectors. ### Claim 10 (depends on 9) The method of claim 9, wherein the prediction block of the current block is generated by using a motion vector generated based on a weighted sum of the scaled plurality of motion vectors. ### Claim 11 (depends on 9) The method of claim 9, wherein a plurality of temporary prediction blocks are generated by respectively using the scaled plurality of motion vectors, and the prediction block of the current block is generated based on a weighted sum of the generated plurality of temporary prediction blocks. ### Claim 12 (depends on 1) The method of claim 1, wherein the deriving of the temporal merge candidate is performed by scaling motion information of the co-located block based on the reference picture for the temporal merge candidate. ### Claim 13 (depends on 12) The method of claim 12, wherein the deriving of the temporal merge candidate by scaling the motion information of the co-located block is selectively performed based on a picture order count value between the current picture including the current block and a reference picture of the current block and a picture order count value between the co-located picture including the co-located block and a reference picture of the co-located block. ### Claim 14 A method for encoding a video, the method comprising: deriving a spatial merge candidate from at least one of spatial candidate blocks of a current block; deriving a temporal merge candidate from a co-located block of the current block; and generating a prediction block of the current block based on at least one of the derived spatial merge candidate and the derived temporal merge candidate, wherein a reference picture for the temporal merge candidate is selected based on a reference picture list of a current picture including the current block and a reference picture list of a co-located picture including the co-located block. ### Claim 15 An apparatus for decoding a video, the apparatus comprising: an inter prediction unit deriving a spatial merge candidate from at least one of spatial candidate blocks of a current block, deriving a temporal merge candidate from a co-located block of the current block, and generating a prediction block of the current block based on at least one of the derived spatial merge candidate and the derived temporal merge candidate, wherein the inter prediction unit selects a reference picture for the temporal merge candidate based on a reference picture list of a current picture including the current block and a reference picture list of a co-located picture including the co-located block. ### Claim 16 An apparatus for encoding a video, the apparatus comprising: an inter prediction unit deriving a spatial merge candidate from at least one of spatial candidate blocks of a current block, deriving a temporal merge candidate from a co-located block of the current block, and generating a prediction block of the current block based on at least one of the derived spatial merge candidate and the derived temporal merge candidate, wherein the inter prediction unit selects a reference picture for the temporal merge candidate based on a reference picture list of a current picture including the current block and a reference picture list of a co-located picture including the co-located block. ### Claim 17 A readable medium storing a bitstream formed by a method for encoding a video, the method including: deriving a spatial merge candidate from at least one of spatial candidate blocks of a current block; deriving a temporal merge candidate from a co-located block of the current block; and generating a prediction block of the current block based on at least one of the derived spatial merge candidate and the derived temporal merge candidate, wherein a reference picture for the temporal merge candidate is selected based on a reference picture list of a current picture including the current block and a reference picture list of a co-located picture including the co-located block.