# US 2021/0344960 A1 · Method for encoding/decoding image and device thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344960 A1 - Document ID: US20210344960A1 - Status: Published application - Kind: A1 - Application number: 17/330,968 - Filed: 2021-05-26 - Published: 2021-11-04 - Earliest claimed: 2011-09-19 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Jaehyun LIM; Seungwook Park; Yongjoon Jeon; Chulkeun Kim; Jungsun Kim; Naeri Park; Hendry Hendry; Byeongmoon Jeon; Joonyoung Park - Web page: https://patentgrep.com/patent/US20210344960A1 ## CPC - H04N 19/61: in combination with predictive coding - H04N 19/124: Quantisation - H04N 19/13: Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] - H04N 19/82: involving filtering within a prediction loop - H04N 19/86: involving reduction of coding artifacts, e.g. of blockiness - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/182: the unit being a pixel - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method for image decoding, according to the present invention, includes the following steps: receiving image information including a plurality of filter coefficients; generating a restored block for a current block on the basis of the image information; and applying an adaptive loop filter to the restored block on the basis of the plurality of filter coefficients. According to the present invention, image encoding efficiency may be improved, and complexity may be reduced. ## Claims ### Claim at position 1 1-14. (canceled) ### Claim 15 An image decoding method by a decoding apparatus, comprising: obtaining prediction information, residual information, and offset information for a sample adaptive offset (SAO) process from a bitstream; deriving prediction samples based on the prediction information; deriving residual samples based on the residual information; generating a reconstructed picture based on the prediction samples and the residual samples; and applying an in-loop filtering process to the reconstructed picture, wherein applying the in-loop filtering process includes applying a deblocking filtering process to the reconstructed picture, and applying the SAO process to a sample in the reconstructed picture to which the deblocking filtering process is completed, wherein the offset information includes offset type information representing that a band offset type is applied to the sample, wherein the offset information includes information on n offset values, and wherein the offset information includes explicit band information indicating one of 32 bands as a starting band of a band group consisting of n bands, and an offset value related to a band among the n bands is applied to the sample, wherein n is an integer. ### Claim 16 (depends on 15) The image decoding method of claim 15, wherein the offset is applied to the sample based on the offset information which is transmitted for a largest coding unit to which the sample belongs. ### Claim 17 (depends on 15) The image decoding method of claim 15, wherein the band is determined as a predetermined sample value range to which the sample belongs. ### Claim 18 (depends on 15) The image decoding method of claim 15, wherein the n bands are specified as the starting band and following bands according to sample value order, wherein the offset value is determined based on the band to which the sample belongs. ### Claim 19 (depends on 15) The image decoding method of claim 15, wherein the n is predetermined as a constant value. ### Claim 20 (depends on 15) The image decoding method of claim 15, wherein the band information further indicates a last band among the n bands. ### Claim 21 An image encoding method by an encoding apparatus, comprising: deriving prediction samples in a current picture based on inter prediction or intra prediction; deriving residual samples in the current picture based on the prediction sample; generating a reconstructed picture of the current picture based on the prediction samples and the residual samples; applying an in-loop filtering process to the reconstructed picture, wherein applying the in-loop filtering process includes applying a deblocking filtering process to the reconstructed picture, and applying a sample adaptive offset (SAO) process to a sample in the reconstructed picture to which the deblocking filtering process is completed; and encoding prediction information on the prediction samples, residual information on the residual samples, and offset information for the SAO process, wherein the offset information includes offset type information representing that a band offset type is applied to the sample, wherein the offset information includes information on n offset values, and wherein the offset information includes explicit band information indicating one of 32 bands as a starting band of a band group consisting of n bands, and an offset value related to a band among the n bands is applied to the sample, wherein n is an integer. ### Claim 22 (depends on 21) The image encoding method of claim 21, wherein the offset is applied to the sample based on the offset information which is transmitted for a largest coding unit to which the sample belongs. ### Claim 23 (depends on 21) The image encoding method of claim 21, wherein the band is determined as a predetermined sample value range to which the sample belongs. ### Claim 24 (depends on 21) The image encoding method of claim 21, wherein the n bands are specified as the starting band and following bands according to sample value order, wherein the offset value is determined based on the band to which the sample belongs. ### Claim 25 (depends on 21) The image encoding method of claim 21, wherein the n is predetermined as a constant value. ### Claim 26 (depends on 21) The image encoding method of claim 21, wherein the band information further indicates a last band among the n bands. ### Claim 27 A non-transitory computer readable digital storage medium storing a bitstream causing a decoding apparatus to perform an image decoding method, the method comprising: obtaining prediction information, residual information, and offset information for a sample adaptive offset (SAO) process from a bitstream; deriving prediction samples based on the prediction information; deriving residual samples based on the residual information; generating a reconstructed picture based on the prediction samples and the residual samples; and applying an in-loop filtering process to the reconstructed picture, wherein applying the in-loop filtering process includes applying a deblocking filtering process to the reconstructed picture, and applying the SAO process to a sample in the reconstructed picture to which the deblocking filtering process is completed, wherein the offset information includes offset type information representing that a band offset type is applied to the sample, wherein the offset information includes information on n offset values, and wherein the offset information includes explicit band information indicating one of 32 bands as a starting band of a band group consisting of n bands, and an offset value related to a band among the n bands is applied to the sample, wherein n is an integer. ### Claim 28 (depends on 27) The non-transitory computer readable digital storage medium of claim 27, wherein the band is determined as a predetermined sample value range to which the sample belongs. ### Claim 29 (depends on 27) The non-transitory computer readable digital storage medium of claim 27, wherein the n bands are specified as the starting band and following bands according to sample value order, wherein the offset value is determined based on the band to which the sample belongs. ### Claim 30 (depends on 27) The non-transitory computer readable digital storage medium of claim 27, wherein the n is predetermined as a constant value. ### Claim 31 (depends on 27) The non-transitory computer readable digital storage medium of claim 27, wherein the band information further indicates a last band among the n bands.