# US 2020/0404302 A1 · Method and device for processing video signal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0404302 A1 - Document ID: US20200404302A1 - Status: Published application - Kind: A1 - Application number: 16/765,027 - Filed: 2018-11-30 - Published: 2020-12-24 - Earliest claimed: 2017-11-30 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Jin HEO - Web page: https://patentgrep.com/patent/US20200404302A1 ## CPC - H04N 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder - H04N 19/103: Selection of coding mode or of prediction mode - 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 19/132: Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking - H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction - 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 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/11: among a plurality of spatial predictive coding modes - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract The present invention relates to a method for decoding a bitstream for a video signal, and a device therefor, and relates to a device and a method in which, according to whether or not intra linear interpolation prediction is performed for the current block, a candidate mode list is formed on the basis of the intra prediction mode of the neighboring block of the current block, a candidate mode is determined, and, on the basis of same, intra LIP is carried out, thereby generating a prediction value for the current block. ## Claims ### Claim 1 A method of decoding a bitstream for a video signal by a decoding apparatus, the method comprising: obtaining a first flag information from the bitstream, the first flag information indicating whether an intra linear interpolation prediction is performed for a current block; when the intra linear interpolation prediction is performed for the current block according to the first flag information, skipping parsing of a second flag information indicating whether an intra prediction mode of the current block is derived from a neighboring block of the current block and obtaining a first index information from the bitstream; constructing a candidate mode list based on an intra prediction mode of the neighboring block of the current block; determining a candidate mode indicated by the first index information in the candidate mode list as the intra prediction mode of the current block; and generating a predictor for the current block by performing an intra LIP based on the determined intra prediction mode. ### Claim 2 (depends on 1) The method of claim 1, wherein performing the LIP comprises: generating a bottom right reference sample for the current block; generating bottom reference samples for the current block, wherein the bottom reference samples include a reference sample generated by performing a first linear interpolation based on a bottom left reference sample adjacent to a bottom left of the current block and the bottom right reference sample, the bottom left reference sample, and reference samples generated by copying left reference samples adjacent to a left of the current block onto same vertical coordinates as the bottom reference samples respectively; and generating a prediction sample by performing a second linear interpolation based on the determined intra prediction mode, the bottom reference samples, and top reference samples adjacent to a top of the current block. ### Claim 3 (depends on 2) The method of claim 2, wherein the bottom right reference sample is generated based on a top right reference sample adjacent to a top right of the current block and the bottom left reference sample. ### Claim 4 (depends on 2) The method of claim 2, wherein the bottom right reference sample is generated based on a bottom right corner reference sample within a top right neighboring block adjacent to a top right of the current block and having a same size as the current block and a bottom right corner reference sample within a bottom left neighboring block adjacent to a bottom left of the current block and having the same size as the current block. ### Claim 5 (depends on 2) The method of claim 2, wherein a weight for the second linear interpolation is determined based on a difference of a vertical coordinate between a sample of the current block and the top reference samples and a difference of a vertical coordinate between the sample of the current block and the bottom reference samples. ### Claim 6 (depends on 1) The method of claim 1, further comprising: when the intra linear interpolation prediction is not performed for the current block according to the first flag information, obtaining the second flag information from the bitstream; when the intra prediction mode of the current block is derived from the neighboring block according to the second flag information, obtaining a second index information from the bitstream and determining a candidate mode indicated by the second index information among the candidate mode list as the intra prediction mode of the current block; and when the intra prediction mode of the current block is not derived from the neighboring block according to the second flag information, obtaining an intra prediction mode information from the bitstream and obtaining the intra prediction mode of the current block based on the intra prediction mode information. ### Claim 7 (depends on 1) The method of claim 1, wherein the candidate mode list is constructed to include 3 candidate modes including at least one of an intra prediction mode of a left neighboring block adjacent to the current block or an intra prediction mode of a top neighboring block adjacent to the current block. ### Claim 8 (depends on 1) The method of claim 1, wherein the candidate mode list is constructed to include 6 candidate modes including at least one of an intra prediction mode of a left neighboring block adjacent to the current block, an intra prediction mode of a bottom left neighboring block adjacent to the current block, an intra prediction mode of a top neighboring block adjacent to the current block, an intra prediction mode of a top left neighboring block adjacent to the current block, or an intra prediction mode of a top right neighboring block adjacent to the current block. ### Claim 9 (depends on 1) The method of claim 1, wherein the candidate mode list includes an intra angular prediction mode other than an intra planar prediction mode and an intra DC prediction mode. ### Claim 10 An apparatus for decoding a bitstream for a video signal, the apparatus comprising: a memory; and a processor connected to the memory upon operation, wherein the processor is configured to: obtain a first flag information from the bitstream, the first flag information indicating whether an intra linear interpolation prediction is performed for a current block; when the intra linear interpolation prediction is performed for the current block according to the first flag information, skip parsing of a second flag information indicating whether an intra prediction mode of the current block is derived from a neighboring block of the current block and obtain a first index information from the bitstream; construct a candidate mode list based on an intra prediction mode of the neighboring block of the current block; determine a candidate mode indicated by the first index information in the candidate mode list as the intra prediction mode of the current block; and generate a predictor for the current block by performing an intra LIP based on the determined intra prediction mode.