# US 11,909,961 B2 · Image encoding/decoding method and apparatus, and recording medium for storing bitstream that involves performing intra prediction using constructed reference sample > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,961 B2 - Document ID: US11909961B2 - Status: Granted - Kind: B2 - Application number: 16/766,611 - Filed: 2018-11-22 - Published: 2021-05-06 - Granted: 2024-02-20 - Earliest claimed: 2017-11-22 - Assignees: Intellectual Discovery Co., Ltd. - Applicants: Intellectual Discovery Co., Ltd. - Inventors: Hyun Suk Ko; Jin Ho Lee; Sung Chang Lim; Jung Won Kang; Ha Hyun Lee; Dong San Jun; Hui Yong Kim - Web page: https://patentgrep.com/patent/US11909961B2 ## CPC - H04N 19/11: among a plurality of spatial predictive coding modes - 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 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/50: using predictive coding (H04N19/61 takes precedence) - H04N 19/593: involving spatial prediction techniques - 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: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract In performing image encoding/decoding, decoding of an image is performed by deriving an intra prediction mode for a current block, decoding at least one original sample that is present in a rightmost column and a bottommost row (a bottom row) of the current block, constructing a reference sample by using the at least one decoded original sample and performing intra prediction on the current block by using the constructed reference sample. ## Claims ### Claim 1 A method of decoding an image, the method comprising: deriving an intra prediction mode for a current block; deriving a reference sample for the current block; and performing intra prediction on the current block by using the derived reference sample, wherein the reference sample is included in a reference sample line, wherein the reference sample line is derived by selecting one reference sample line among a plurality of neighboring reference sample lines of the current block based on a position of the current block within a coding tree block, wherein when an upper boundary of the current block, partitioned from the coding tree block, corresponds to an upper boundary of the coding tree block, the reference sample line is derived by selecting a reference sample line closest to the current block, wherein the reference sample is derived by performing filtering samples of the selected reference sample line only when the selected reference sample line is the reference sample line closest to the current block among the plurality of neighboring reference sample lines, and wherein the filtering is performed only using the reference sample of the reference sample line closest to the current block. ### Claim 2 (depends on 1) The method of claim 1, wherein the reference sample line is derived based on a reference sample line indicator obtained from a bitstream. ### Claim 3 (depends on 2) The method of claim 2, wherein the reference sample line indicator indicates which of the plurality of neighboring reference sample lines is a reference sample line. ### Claim 4 (depends on 2) The method of claim 2, when an upper boundary of the current block corresponds to a boundary of a coding tree block, wherein the reference sample line indicator is not obtained from the bitstream and is set to a predetermined value. ### Claim 5 (depends on 1) The method of claim 1, when the reference sample corresponds to a predetermined position, the reference sample is derived by padding a sample adjacent to the predetermined position without determining availability of the block at the predetermined position. ### Claim 6 (depends on 1) The method of claim 1, when the current block is a combined prediction of intra prediction and inter prediction, the intra prediction mode for the current block is fixed to a planar mode. ### Claim 7 (depends on 4) The method of claim 4, when an upper boundary of the current block corresponds to a boundary of a coding tree block, wherein the reference sample line indicator set to the predetermined value indicates the reference sample line closest to the current block. ### Claim 8 A method of encoding an image, the method comprising: deriving an intra prediction mode for a current block; deriving a reference sample for the current block; and performing intra prediction on the current block by using the derived reference sample, wherein the reference sample is included in a reference sample line, wherein the reference sample line is derived by selecting one reference sample line among a plurality of neighboring reference sample lines of the current block based on a position of the current block within a coding tree block, wherein when an upper boundary of the current block, partitioned from the coding tree block, corresponds to an upper boundary of the coding tree block, the reference sample line is derived by selecting a reference sample line closest to the current block, wherein the reference sample is derived by performing filtering samples of the selected reference sample line only when the selected reference sample line is the reference sample line closest to the current block among the plurality of neighboring reference sample lines, and wherein the filtering is performed only using the reference sample of the reference sample line closest to the current block. ### Claim 9 A non-transitory storage medium storing a bitstream generated by a method of encoding an image, the method including: deriving an intra prediction mode for a current block; deriving a reference sample for the current block; and performing intra prediction on the current block by using the derived reference sample, wherein the reference sample is included in a reference sample line, wherein the reference sample line is derived by selecting one reference sample line among a plurality of neighboring reference sample lines of the current block based on a position of the current block within a coding tree block, wherein when an upper boundary of the current block, partitioned from the coding tree block, corresponds to an upper boundary of the coding tree block, the reference sample line is derived by selecting a reference sample line closest to the current block, wherein the reference sample is derived by performing filtering samples of the selected reference sample line only when the selected reference sample line is the reference sample line closest to the current block among the plurality of neighboring reference sample lines, and wherein the filtering is performed only using the reference sample of the reference sample line closest to the current block.