# US 10,123,047 B2 · Method and apparatus for image encoding/decoding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,123,047 B2 - Document ID: US10123047B2 - Status: Granted - Kind: B2 - Application number: 15/887,062 - Filed: 2018-02-02 - Published: 2018-06-07 - Granted: 2018-11-06 - Earliest claimed: 2013-02-28 - Assignees: Research & Business Foundation Sungkyunkwan University - Applicants: Research & Business Foundation Sungkyunkwan University - Inventors: Byeung Woo Jeon; Kwang Hyun Won - Web page: https://patentgrep.com/patent/US10123047B2 ## CPC - H04N 19/61: in combination with predictive coding - H04N 19/12: Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264 - H04N 19/14: Coding unit complexity, e.g. amount of activity or edge presence estimation (H04N19/146 takes precedence) - H04N 19/154: Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion (use of rate-distortion criteria H04N19/147) - H04N 19/157: Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/625: using discrete cosine transform [DCT] - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Disclosed are a method and an apparatus for image encoding/decoding. The method for image decoding includes comparing whether a size of a current transform block and a size of a smallest transform block (smallest transform unit (STU)) are the same as each other, and decoding information indicating whether transformation is performed on the current transform block and determining whether to perform inverse transformation on the current transform block based on the decoded information indicating whether the transformation is performed when the size of the current transform block and the size of a smallest transform block are the same as each other. ## Claims ### Claim 1 A method of decoding an image, comprising: generating a prediction block for a current block; receiving information of a first block size, wherein the information of the first block size is determined by an encoder, and wherein whether a skip of a transform process is applicable is determined based on a comparison of the information of the first block size with a current block size; decoding information indicating whether the skip of the transform process is applied, in response to the comparison of the information of the first block size with the current block size representing that the skip of the transform process is applicable; determining whether to perform an inverse transform on the current block based on the decoded information indicating whether the skip of the transform process is applied; performing the inverse transform on the current block to generate a residual block for the current block; reconstructing the current block based on the prediction block and the residual block; and applying filtering on the reconstructed current block, wherein the prediction block is generated by performing intra prediction, and wherein the filtering comprises either one or both of deblocking filtering and a-sample adaptive offset (SAO) filtering. ### Claim 2 (depends on 1) The method of claim 1, wherein in response to the decoded information indicating that the transform process is not performed, the inverse transform on the current block is skipped. ### Claim 3 (depends on 1) The method of claim 1, wherein in response to the decoded information indicating that the transform process is performed, the inverse transform on the current block is performed. ### Claim 4 (depends on 1) The method of claim 1, wherein in response to a value of transform_skip_flag being 1, the transform process is not performed and is skipped on the current block, and in response to the value of transform_skip_flag being 0, the transform process is performed on the current block. ### Claim 5 (depends on 4) The method of claim 4, wherein the information indicating whether the skip of the transform process is applied comprises a flag indicating whether to perform the inverse transform on the current block based on the information of the first block size. ### Claim 6 (depends on 1) The method of claim 1, further comprising performing an inverse transform on the current block according to the current block size, in response to the current block size satisfying a condition in which the skip of the transform process is not applied. ### Claim 7 (depends on 6) The method of claim 6, wherein the skip of the transform process is applied when the current block size is larger than 4×4 pixels. ### Claim 8 An apparatus to decode an image, comprising: at least one processor configured to generate a prediction block for a current block, decode information of a first block size and information indicating whether a skip of a transform process is applied, wherein the information of the first block size is determined by an encoder, and wherein whether the skip of the transform process is applicable is determined based on a comparison of the information of the first block size with a current block size, determine whether to perform an inverse transform on the current block based on the decoded information indicating whether the skip of the transform process is applied, perform the inverse transform on the current block to generate a residual block for the current block, reconstruct the current block based on the prediction block and the residual block, and apply filtering on the reconstructed current block, wherein the prediction block is generated by performing intra prediction, and wherein the filtering comprises either one or both of deblocking filtering and sample adaptive offset (SAO) filtering. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the skip of the transform process is applied when the current block size is larger than 4×4 pixels. ### Claim 10 A method of encoding an image, comprising: generating a prediction block for a current block; generating a residual block for the current block based on the prediction block; encoding the residual block; decoding the encoded residual block; reconstructing the current block based on the prediction block and the decoded residual block; and applying filtering on the reconstructed current block, wherein the prediction block is generated by performing intra prediction, wherein the filtering comprises either one or both of deblocking filtering and sample adaptive offset (SAO) filtering, and wherein the encoding of the residual block comprises determining information of a first block size, wherein whether a skip of a transform process is applicable is determined based on the information of the first block size compared with a current block size; determining whether to apply the skip of the transform process on the current block based on a comparison of the information of the first block size with a current block size; and performing a transform on the current block to encode the residual block. ### Claim 11 (depends on 10) The method of claim 10, further comprising encoding the information indicating whether the skip of the transform process is applied to the current block. ### Claim 12 (depends on 10) The method of claim 10, wherein in response to a value of transform_skip_flag being 1, the transform process is not performed and is skipped on the current block, and in response to the value of transform_skip_flag being 0, the transform process is performed on the current block. ### Claim 13 (depends on 11) The method of claim 11, wherein in response to a determination that the skip of the transform process is applied to the current block, the information indicating whether the skip of the transform process is applied to the current block indicates that the transform on the current block is skipped. ### Claim 14 (depends on 11) The method of claim 11, wherein in response to a determination that that the skip of the transform process is not applied to the current block, the information indicating whether the skip of the transform process is applied to the current block indicates that the transform on the current block is performed. ### Claim 15 (depends on 13) The method of claim 13, further comprising performing the transform on the current block according to the current block size, in response to the current block size satisfying a condition in which the skip of the transform process is not applied. ### Claim 16 (depends on 12) The method of claim 12, wherein the information indicating whether the skip of the transform process is applied comprises a flag indicating whether to perform the transform on the current block based on the information of the first block size. ### Claim 17 (depends on 16) The method of claim 16, wherein the skip of the transform process is applied when the current block size is larger than 4×4 pixels. ### Claim 18 An apparatus to encode an image, comprising: at least one processor, configured to generate a prediction block for a current block, generate a residual block for the current block based on the prediction block, encode the residual block, decode the encoded residual block, reconstruct the current block based on the prediction block and the decoded residual block, and apply filtering on the reconstructed current block, wherein the prediction block is generated by performing intra prediction, wherein the filtering comprises either one or both of deblocking filtering and sample adaptive offset (SAO) filtering, and wherein the encoding of the residual block comprises performing a transform on the current block based on information indicating whether a skip of a transform process is applied, and encoding information of a first block size and the information indicating whether the skip of the transform process is applied, wherein whether the skip of the transform process is applicable is determined based on a comparison of the information of the first block size with a current block size. ### Claim 19 (depends on 18) The apparatus of claim 18, wherein the skip of the transform process is applied when the current block size is larger than 4×4 pixels.