# US 2014/0192886 A1 · Method and Apparatus for Encoding an Image Into a Video Bitstream and Decoding Corresponding Video Bitstream Using Enhanced Inter Layer Residual Prediction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192886 A1 - Document ID: US20140192886A1 - Status: Published application - Kind: A1 - Application number: 14/147,380 - Filed: 2014-01-03 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Edouard FRANÇOIS; Christophe GISQUET; Patrice ONNO; Guillaume LAROCHE - Web page: https://patentgrep.com/patent/US20140192886A1 ## CPC - H04N 19/33: in the spatial domain - H04N 19/503: involving temporal prediction (adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109) - H04N 19/80: Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation (H04N19/635, H04N19/86 take precedence) - 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 19/59: involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method for encoding an image of pixels and for decoding a corresponding bit stream is described. More particularly, it concerns residual prediction according to a spatial scalable encoding scheme. It can be considered in the context of the Scalable extension of the HEVC standard (noted SHVC), being developed by the ISO-MPEG and ITU-T standardization organizations. It is proposed to simplify the computational complexity and the memory usage needed by the GRILP and DIFF inter modes by combining upsampling and motion compensation operations into one single operation and/or reducing the complexity of the linear filtering processes involved in some of the processes and/or adopt some limiting usage of these two modes when combined with bidirectional prediction. Accordingly a reduction of the complexity is achieved with, at worst, a limited loss in coding efficiency. ## Claims ### Claim 1 A method for encoding an image of pixels according to a scalable encoding scheme having an enhancement layer and a reference layer, the method comprising for the encoding of a coding block in the enhancement layer in a coding mode called GRILP or DIFF inter: (a) determining a predictor of said coding block in the enhancement layer and the associated motion vector by a motion compensation step; (b) determining a first predictor block of the coding block; (c) determining a residual predictor block based on said motion compensation step and the reference layer; (d) determining a second predictor block by adding the first predictor block and said residual predictor block; (e) predictive encoding of the coding block using said second predictor block; wherein at least one of the steps (a) to (e) involving an application of a single concatenated filter for cascading successive elementary filtering processes related to block processing including motion compensation and/or block upsampling and/or block filtering. ### Claim 2 (depends on 1) A method according to claim 1, wherein the determined first predictor block of the coding block is the determined predictor of said coding block in the enhancement layer. ### Claim 3 (depends on 1) A method according to claim 1, wherein the determined first predictor block of the coding block is the block in the reference layer co-located to said coding block. ### Claim 4 (depends on 1) A method according to claim 1, wherein the single concatenated filter is based on the convolution of at least two elementary filters, each elementary filter corresponding to an elementary mathematical operator. ### Claim 5 (depends on 4) A method according to claim 4, wherein the at least two elementary mathematical operators are the upsampling process of the reference base layer picture resulting in the upsampled reference base layer picture, and the motion compensation process of the upsampled reference base layer picture. ### Claim 6 (depends on 1) A method according to claim 1, wherein the single concatenated filter is based on a pre-determined interpolation filter derived from a Discrete Cosine Transform. ### Claim 7 (depends on 1) A method according to claim 1, wherein the single concatenated filter is based on a pre-determined interpolation filter derived from the resolution of linear equations systems function of the phases. ### Claim 8 (depends on 6) A method according to claim 6, wherein an image comprising at least two colour components, the pre-determined interpolation filter comprises specific values to be applied to each colour component. ### Claim 9 (depends on 1) A method according to claim 1, wherein said concatenated filter is further convolved by an attenuation window in order to reduce the filter size. ### Claim 10 (depends on 1) A method according to claim 1, wherein the method further comprises: forbidding the GRILP encoding mode and the DIFF inter encoding mode for coding block subject to bi-predictive encoding. ### Claim 11 A method for encoding an image of pixels according to a scalable encoding scheme having an enhancement layer and a reference layer, the method comprising for the encoding of a coding block in the enhancement layer in a coding mode called GRILP or DIFF inter: (a) determining a predictor of said coding block in the enhancement layer and the associated motion vector by a motion compensation step; (b) determining a first predictor block of the coding block; (c) determining a residual predictor block based on said motion compensation step and the reference layer; (d) determining a second predictor block by adding the first predictor block and said residual predictor block; (e) predictive encoding of the coding block using said second predictor block; and wherein the method further comprises: (f) forbidding the GRILP encoding mode and the DIFF inter encoding mode, or enabling the GRILP encoding mode or the DIFF inter encoding mode based on information pertaining to the reference picture, or enabling the GRILP encoding mode or the DIFF inter encoding mode based on the size of the coding block, or enabling the GRILP encoding mode or the DIFF inter encoding mode based on the size of the block in the reference layer collocated to the coding block, or disabling the GRILP encoding mode or the DIFF inter encoding mode for coding block when at least one of the collocated block in the reference layer is subject to bi-predictive encoding, for coding block subject to bi-predictive encoding. ### Claim 12 (depends on 1) A method according to claim 1, wherein the method further comprises: limiting the accuracy of the motion compensation step for coding blocks subject to bi-predictive encoding. ### Claim 13 (depends on 1) A method according to claim 1, wherein the method further comprises: limiting the filter size used in the motion compensation step for coding blocks subject to bi-predictive encoding. ### Claim 14 A method for decoding a bit stream comprising data representing an image encoded according to a scalable encoding scheme having an enhancement layer and a reference layer, the method comprising for the decoding of said enhancement layer: (a) obtaining from the bit stream the motion vector associated to a prediction of a coding block within the enhancement layer to be decoded and a residual block; (b) determining a residual predictor block based on said location and the reference layer; (c) determining a first predictor block of the coding block; (d) determining a second predictor block by adding the first predictor block and said residual predictor block; (e) reconstructing the coding unit using the second predictor block and the obtained residual block; wherein at least one of the steps (b) to (e) involving an application of a single concatenated filter for cascading successive elementary filtering processes related to block processing including motion compensation and/or block upsampling and/or block filtering. ### Claim 15 (depends on 14) A method according to claim 14, wherein the determined first predictor block of the coding block is the predictor block associated with the obtained motion vector in the enhancement layer. ### Claim 16 (depends on 14) A method according to claim 14, wherein the determined first predictor block of the coding block is the block in the reference layer co-located to said coding block. ### Claim 17 (depends on 14) A method according to claim 14, wherein the single concatenated filter is based on the convolution of at least two elementary filters, each elementary filter corresponding to an elementary mathematical operator. ### Claim 18 (depends on 17) A method according to claim 17, where the at least two elementary mathematical operators are the upsampling process of the reference base layer picture resulting in the upsampled reference base layer picture, and the motion compensation process of the upsampled reference base layer picture. ### Claim 19 (depends on 14) A method according to claim 14, wherein the single concatenated filter is based on a pre-determined interpolation filter derived from a Discrete Cosine Transform. ### Claim 20 (depends on 14) A method according to claim 14, wherein the single concatenated filter is based on a pre-determined interpolation filter derived from the resolution of linear equations systems based dependent on the phases of the filter. ### Claim 21 (depends on 19) A method according to claim 19, wherein an image comprising at least two colour components, the pre-determined interpolation filter comprises specific values to be applied to each colour component. ### Claim 22 (depends on 14) A method according to claim 14, wherein said concatenated filter is further convolved by an attenuation window in order to reduce the filter size. ### Claim 23 (depends on 14) A method according to claim 14, wherein the motion vector obtained in the enhancement layer being determined according to a given accuracy, the method further comprises: down sampling said motion vector to be used in the reference layer with an accuracy lower than the accuracy theoretically given based on the given accuracy and the spatial scalability ratio between the reference layer and the enhancement layer. ### Claim 24 (depends on 14) A method according to claim 14, wherein the method further comprises: limiting the accuracy of the motion compensation step for decoding blocks subject to bi-predictive encoding. ### Claim 25 (depends on 14) A method according to claim 14, wherein the method further comprises: limiting the filter size used in the motion compensation step for decoding blocks subject to bi-predictive encoding. ### Claim 26 A method for encoding or decoding an image of pixels according to a scalable format having an enhancement layer and a reference layer, the method comprising for the encoding or the decoding of a coding block in the enhancement layer: (a) determining a first predictor of said coding block in the enhancement layer using an associated motion vector; (b) determining a second predictor block co-located to the first predictor block in the base layer; (c) determining a residual predictor block as the difference between the first and the second predictor block; (d) motion compensating the residual predictor block using the associated motion vector; (e) obtaining a third predictor block by adding the motion compensated residual block to the block of the base layer co-located to the coding block (f) predicting the coding block using said third predictor block; Wherein the first predictor is down-sampled to the resolution of the base layer before the determination of the residual predictor block. ### Claim 27 (depends on 26) A method according to claim 26 wherein the associated motion vector is down-sampled to the base layer resolution before motion compensating the residual predictor block ### Claim 28 (depends on 26) A method according to claim 26 where the third predictor block is up-sampled to the resolution of the enhancement layer before the predicting step. ### Claim 29 A device for encoding an image of pixels according to a scalable encoding scheme having an enhancement layer and a reference layer, the device comprising for the encoding of a coding block in the enhancement layer in a coding mode called GRILP or DIFF inter: (a) means for determining a predictor of said coding block in the enhancement layer and the associated motion vector by a motion compensation step; (b) means for determining a first predictor block of the coding block; (c) means for determining a residual predictor block based on said motion compensation step and the reference layer; (d) means for determining a second predictor block by adding the first predictor block and said residual predictor block; (e) means for predictive encoding of the coding block using said second predictor block; and wherein the device further comprises: (f) means for forbidding the GRILP encoding mode and the DIFF inter encoding mode, or enabling the GRILP encoding mode or the DIFF inter encoding mode based on information pertaining to the reference picture, or enabling the GRILP encoding mode or the DIFF inter encoding mode based on the size of the coding block, or enabling the GRILP encoding mode or the DIFF inter encoding mode based on the size of the block in the reference layer collocated to the coding block, or disabling the GRILP encoding mode or the DIFF inter encoding mode for coding block when at least one of the collocated block in the reference layer is subject to bi-predictive encoding, for coding block subject to bi-predictive encoding. ### Claim 30 A device for decoding a bit stream comprising data representing an image encoded according to a scalable encoding scheme having an enhancement layer and a reference layer, the device comprising for the decoding of said enhancement layer: (a) means for obtaining from the bit stream the motion vector associated to a prediction of a coding block within the enhancement layer to be decoded and a residual block; (b) means for determining a residual predictor block based on said location and the reference layer; (c) means for determining a first predictor block of the coding block; (d) means for determining a second predictor block by adding the first predictor block and said residual predictor block; (e) means for reconstructing the coding unit using the second predictor block and the obtained residual block; wherein at least one of the means (b) to (e) is configured for an application of a single concatenated filter for cascading successive elementary filtering processes related to block processing including motion compensation and/or block upsampling and/or block filtering. ### Claim 31 A device for encoding or decoding an image of pixels according to a scalable format having an enhancement layer and a reference layer, the device comprising for the encoding or the decoding of a coding block in the enhancement layer: (a) a means for determining a first predictor of said coding block in the enhancement layer using an associated motion vector; (b) a means for determining a second predictor block co-located to the first predictor block in the base layer; (c) a means for determining a residual predictor block as the difference between the first and the second predictor block; (d) a means for motion compensating the residual predictor block using the associated motion vector; (e) a means for obtaining a third predictor block by adding the motion compensated residual block to the block of the base layer co-located to the coding block (e) a means for predicting the coding block using said third predictor block; Wherein the device comprises a means for down-sampling the first predictor to the resolution of the base layer before the determination of the residual predictor block. ### Claim 32 (depends on 31) A device according to claim 31 wherein the associated motion vector is down-sampled to the base layer resolution before motion compensating the residual predictor block ### Claim 33 (depends on 31) A device according to claim 31 where the third predictor block is up-sampled to the resolution of the enhancement layer before the predicting step. ### Claim 34 (depends on 1) A computer-readable storage medium storing instructions of a computer program for implementing a method according claim 1.