# US 2020/0288146 A1 · Intra-prediction mode-based image processing method and apparatus therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0288146 A1 - Document ID: US20200288146A1 - Status: Published application - Kind: A1 - Application number: 15/932,376 - Filed: 2016-05-02 - Published: 2020-09-10 - Earliest claimed: 2015-08-17 - Applicants: LG Electronics Inc. - Inventors: Yongjoon JEON; Jin HEO; Sunmi YOO - Web page: https://patentgrep.com/patent/US20200288146A1 ## 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 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/593: involving spatial prediction techniques - H04N 19/82: involving filtering within a prediction loop - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image processing method based on an intra-prediction mode and an apparatus for the same. Particularly, the method may include deriving an intra-prediction mode of a current block, constructing a reference sample to be used for a prediction of the current block from a neighboring sample of the current block, generating a prediction block of the current block based on the intra-prediction mode by using the reference sample, and performing a post filtering by using an adjacent sample of the prediction sample for each prediction sample in the prediction block. ## Claims ### Claim 1 A method for processing an image based on an intra-prediction mode, the method comprising: deriving an intra-prediction mode of a current block; constructing a reference sample to be used for a prediction of the current block from a neighboring sample of the current block; generating a prediction block of the current block based on the intra-prediction mode by using the reference sample; and performing a post filtering by using an adjacent sample of a prediction sample for each prediction sample in the prediction block. ### Claim 2 (depends on 1) The method for processing an image based on an intra-prediction mode of claim 1, further comprising receiving a filter index from an encoding apparatus, wherein an adjacent sample used in the post filtering and/or a filter coefficient used in the post filtering are/is determined depending on the filter index. ### Claim 3 (depends on 1) The method for processing an image based on an intra-prediction mode of claim 1, wherein an adjacent sample used in the post filtering and/or a filter coefficient used in the post filtering are/is determined depending on the intra-prediction mode. ### Claim 4 (depends on 3) The method for processing an image based on an intra-prediction mode of claim 3, wherein the post filtering is performed by using only a top adjacent sample of the prediction sample, when the intra-prediction mode is a horizontal mode. ### Claim 5 (depends on 3) The method for processing an image based on an intra-prediction mode of claim 3, wherein the post filtering is performed by using only a left adjacent sample of the prediction sample, when the intra-prediction mode is a vertical mode. ### Claim 6 (depends on 3) The method for processing an image based on an intra-prediction mode of claim 3, further comprising receiving information indicating whether to apply the post filtering to the current block, wherein whether to apply the post filtering to the current block is determined according to the information. ### Claim 7 (depends on 1) The method for processing an image based on an intra-prediction mode of claim 1, wherein the post filtering is performed by using a left adjacent sample and/or a top adjacent sample of the prediction sample. ### Claim 8 (depends on 1) The method for processing an image based on an intra-prediction mode of claim 1, wherein the adjacent sample used for the post filtering is a sample before the post filtering is applied. ### Claim 9 (depends on 1) The method for processing an image based on an intra-prediction mode of claim 1, wherein the adjacent sample used for the post filtering is a sample to which the post filtering is applied. ### Claim 10 (depends on 1) The method for processing an image based on an intra-prediction mode of claim 1, wherein the post filtering is applied to the current block, when a size of the current block is greater than a predetermined size and/or when the intra-prediction mode is a directional mode. ### Claim 11 (depends on 10) The method for processing an image based on an intra-prediction mode of claim 10, wherein a filtering is not applied to the reference sample, when the post filtering is applied to the current block. ### Claim 12 (depends on 10) The method for processing an image based on an intra-prediction mode of claim 10, wherein a filtering is not applied to a left end sample and/or a top end sample within the prediction block even when the intra-prediction mode is DC mode, a horizontal mode or a vertical mode, when the post filtering is applied to the current block. ### Claim 13 An apparatus for processing an image based on an intra-prediction mode, the apparatus comprising: a prediction mode derivation unit for deriving an intra-prediction mode of a current block; a reference sample construction unit for constructing a reference sample to be used for a prediction of the current block from a neighboring sample of the current block; a prediction block generation unit for generating a prediction block of the current block based on the intra-prediction mode by using the reference sample; and a post filtering unit for performing a post filtering by using an adjacent sample of a prediction sample for each prediction sample in the prediction block.