# US 12,003,752 B2 · Method and device for encoding and decoding image > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,752 B2 - Document ID: US12003752B2 - Status: Granted - Kind: B2 - Application number: 18/200,085 - Filed: 2023-05-22 - Published: 2023-09-21 - Granted: 2024-06-04 - Earliest claimed: 2012-01-18 - Assignees: Electronics and Telecommunications Research Institute - Applicants: Electronics and Telecommunications Research Institute - Inventors: Hui Yong Kim; Jin Ho Lee; Sung Chang Lim; Jin Soo Choi; Jin Woong Kim - Web page: https://patentgrep.com/patent/US12003752B2 ## CPC - H04N 19/51: Motion estimation or motion compensation - 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 19/182: the unit being a pixel - 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 19/42: characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation (H04N19/635 takes precedence) - H04N 19/513: Processing of motion vectors - H04N 19/52: by predictive encoding - 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 decoding method according to the present invention includes reconstructing a residual block by inverse-quantizing and inverse-transforming an entropy-decoded residual block, generating a prediction block by performing intra prediction on a current block, and reconstructing an picture by adding the reconstructed residual block to the prediction block, wherein generating the prediction block includes generating a final prediction value of a prediction target pixel included in the current block based on a first prediction value of the prediction target pixel and a final correction value calculated by performing an arithmetic right shift on a two's complementary integer representation for an initial correction value of the prediction target pixel by a binary digit of 1. Accordingly, upon image encoding/decoding, computation complexity may be reduced. ## Claims ### Claim 1 A video decoding method comprising: generating a prediction block by performing intra prediction for a current block; deriving transform coefficients of the current block by entropy-decoding a bitstream; performing inverse-quantization on the derived transform coefficients; reconstructing a residual block by performing inverse-transformation on the inverse-quantized transform coefficients; and reconstructing the current block based on the reconstructed residual block and the prediction block, wherein the generating the prediction block comprises obtaining a first prediction value of a prediction target pixel of the prediction block; determining an initial correction value of the prediction target pixel; calculating a final correction value of the prediction target pixel by performing an arithmetic right shift on the initial correction value by a binary digit of n, n being an integer equal to or greater than 1; and generating a final prediction value of the prediction target pixel based on the first prediction value and the final correction value. ### Claim 2 (depends on 1) The video decoding method of claim 1, wherein whether to correct the first prediction value is determined depending on encoding information on the current block and a position of the prediction target pixel in the prediction block and the final prediction value of the prediction target pixel is generated based on a result of the determination. ### Claim 3 (depends on 2) The video decoding method of claim 2, wherein the encoding information comprises at least one of an intra prediction mode, luma signal information, chroma signal information and a block size of the current block. ### Claim 4 (depends on 2) The video decoding method of claim 2, wherein a pixel on a left boundary of the current block is corrected when an intra prediction mode of the current block is a vertical prediction mode. ### Claim 5 A video encoding method comprising: generating a prediction block by performing intra prediction for a current block; obtaining a residual block based on the prediction block and the current block; deriving transform coefficients of the current block by performing transformation on the obtained residual block; performing quantization on the derived transform coefficients; and entropy-encoding the quantized transform coefficients into a bitstream, wherein the generating the prediction block comprises obtaining a first prediction value of a prediction target pixel of the prediction block; determining an initial correction value of the prediction target pixel; calculating a final correction value of the prediction target pixel by performing an arithmetic right shift on the initial correction value by a binary digit of n, n being an integer equal to or greater than 1; and generating a final prediction value of the prediction target pixel based on the first prediction value and the final correction value. ### Claim 6 (depends on 5) The video encoding method of claim 5, wherein whether to correct the first prediction value is determined depending on encoding information on the current block and a position of the prediction target pixel in the prediction block and the final prediction value of the prediction target pixel is generated based on a result of the determination. ### Claim 7 (depends on 6) The video encoding method of claim 6, wherein the encoding information comprises at least one of an intra prediction mode, luma signal information, chroma signal information and a block size of the current block. ### Claim 8 (depends on 6) The video encoding method of claim 6, wherein a pixel on a left boundary of the current block is corrected when an intra prediction mode of the current block is a vertical prediction mode. ### Claim 9 A method for transmitting a bitstream performed by a video encoding apparatus, wherein the method comprising: generating a prediction block by performing intra prediction for a current block; obtaining a residual block based on the prediction block and the current block; deriving transform coefficients of the current block by performing transformation on the obtained residual block; performing quantization on the derived transform coefficients; and entropy-encoding the quantized transform coefficients into a bitstream, transmitting the bitstream to a video decoding apparatus, wherein the generating the prediction block comprises obtaining a first prediction value of a prediction target pixel of the prediction block; determining an initial correction value of the prediction target pixel; calculating a final correction value of the prediction target pixel by performing an arithmetic right shift on the initial correction value by a binary digit of n, n being an integer equal to or greater than 1; and generating a final prediction value of the prediction target pixel based on the first prediction value and the final correction value. ### Claim 10 (depends on 9) The method of claim 9, wherein the bitstream comprises encoding information on the current block, wherein whether to correct the first prediction value is determined depending on the encoding information on the current block and a position of the prediction target pixel in the prediction block and wherein the final prediction value of the prediction target pixel is generated based on a result of the determination. ### Claim 11 (depends on 10) The method of claim 10, wherein the encoding information comprises at least one of an intra prediction mode, luma signal information, chroma signal information and a block size of the current block. ### Claim 12 (depends on 10) The method of claim 10, wherein a pixel on a left boundary of the current block is corrected when an intra prediction mode of the current block is a vertical prediction mode.