# US 2019/0246103 A1 · Method and apparatus for encoding and decoding image, and recording medium for storing bitstream > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0246103 A1 - Document ID: US20190246103A1 - Status: Published application - Kind: A1 - Application number: 16/336,264 - Filed: 2017-09-26 - Published: 2019-08-08 - Earliest claimed: 2016-10-04 - 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/US20190246103A1 ## CPC - H04N 19/109: among a plurality of temporal predictive coding modes - H04N 19/52: by predictive encoding - H04N 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) - H04N 19/119: Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks - H04N 19/132: Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking - H04N 19/172: the region being a picture, frame or field - H04N 19/174: the region being a slice, e.g. a line of blocks or a group of blocks - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/182: the unit being a pixel - H04N 19/513: Processing of motion vectors - H04N 19/86: involving reduction of coding artifacts, e.g. of blockiness - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image encoding method and an image decoding method are provided. The image decoding method includes deriving a temporal merge candidate from a co-located block of a current block, generating a merge candidate list of the current block based on the derived temporal merge candidate, and generating a prediction block of the current block based on the generated merge candidate list. The deriving a temporal merge candidate includes scaling a motion vector derived from the co-located block based on a POC difference value between the current block and a reference picture of the current block and a POC difference value between the co-located block and a reference picture of the co-located block, and modifying the scaled motion vector based on motion vector scaling information between a neighboring block of the current block and a co-located block of the neighboring block. ## Claims ### Claim 1 A method for decoding an image, the method comprising: deriving a temporal merge candidate from a co-located block of a current block; generating a merge candidate list of the current block based on the derived temporal merge candidate; and generating a prediction block of the current block based on the generated merge candidate list, wherein the deriving a temporal merge candidate comprises: scaling a motion vector derived from the co-located block based on a POC (Picture Order Count) difference value between the current block and a reference picture of the current block and a POC difference value between the co-located block and a reference picture of the co-located block; and modifying the scaled motion vector based on motion vector scaling information between neighboring blocks of the current block and co-located blocks of the neighboring blocks. ### Claim 2 (depends on 1) The image decoding method according to claim 1, wherein the deriving a temporal merge candidate further comprises: scaling a motion vector derived from the co-located block of the neighboring block, based on a POC difference value between the neighboring block and a reference picture of the neighboring block and a POC difference value between the co-located block of the neighboring block and a reference picture of the co-located block of the neighboring block; and generating motion vector scaling information between the neighboring block and the co-located block of the neighboring block based on a ratio of a motion vector derived from the co-located block of the neighboring block and then scaled and a motion vector of the neighboring block. ### Claim 3 (depends on 1) The image decoding method according to claim 1, wherein the modifying the scaled motion vector is performed by applying a weighted value based on the motion vector scaling information between the neighboring block and the co-located block of the neighboring block to the scaled motion vector. ### Claim 4 (depends on 3) The image decoding method according to claim 3, wherein when the POC difference value between the current block and the reference picture of the current block differs from the POC difference value between the neighboring block and the reference picture of the neighboring block, the weighted value is modified based on a difference value between the POC difference values. ### Claim 5 (depends on 1) The image decoding method according to claim 1, wherein the neighboring block is selected among spatial neighboring blocks of the current block and temporal neighboring blocks of the current block based on neighboring block position information. ### Claim 6 (depends on 1) The image decoding method according to claim 1, wherein the neighboring block is a block that is selected among spatial neighboring blocks of the current block and has a reference picture the same as the reference picture of the current block. ### Claim 7 An image encoding method comprising: deriving a temporal merge candidate from a co-located block of a current block; generating a merge candidate list of the current block, based on the derived temporal merge candidate; and generating a prediction block of the current block, based on the generated merge candidate list, wherein the deriving a temporal merge candidate comprises: scaling a motion vector derived from the co-located block, based on a POC difference value between the current block and a reference picture of the current block and a POC difference value between the co-located block and a reference picture of the co-located block; and modifying the scaled motion vector, based on motion vector scaling information between spatial and temporal neighboring blocks of the current block and co-located blocks of the spatial and temporal neighboring blocks. ### Claim 8 (depends on 7) A recording medium storing a bitstream generated through the image encoding method of claim 7. ### Claim 9 An image decoding method comprising: acquiring an inter-picture prediction indicator indicating an inter-picture prediction direction and an inter-picture prediction mode; and generating a prediction block of a current block based on the inter-picture prediction indicator, wherein the inter-picture prediction indicator indicates the inter-picture prediction mode for each prediction direction. ### Claim 10 An image encoding method comprising: determining an inter-picture prediction mode for each inter-picture prediction direction; and encoding the inter-picture prediction indicator indicating an inter-picture prediction direction and an inter-picture prediction mode according to a result of the determining. ### Claim 11 (depends on 10) A recording medium storing a bitstream generated through the encoding method of claim 10. ### Claim 12 An image decoding apparatus comprising: a motion compensation unit deriving a temporal merge candidate from a co-located block of a current block, generating a merge candidate list based on the derived temporal merge candidate, and generating a prediction block of the current block based on the generated merge candidate list, wherein the motion compensation unit performs: scaling a motion vector derived from the co-located block based on a POC difference value between the current block and a reference picture of the current block and a POC difference value between the co-located block and a reference picture of the co-located block; and modifying the scaled the motion vector based on motion vector scaling information between a neighboring block of the current block and a co-located block of the neighboring block. ### Claim 13 An image decoding apparatus comprising: an entropy decoding unit acquiring an inter-picture prediction indicator indicating an inter-picture prediction direction and an inter-picture prediction mode; and a motion compensation unit generating a prediction block of a current block based on the inter-picture prediction indicator, wherein the inter-picture prediction indicator indicates an inter-picture prediction mode for each prediction direction.