# US 2025/0159162 A1 · Method and apparatus for selecting a coding mode used for encoding/decoding a residual block > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0159162 A1 - Document ID: US20250159162A1 - Status: Published application - Kind: A1 - Application number: 19/025,682 - Filed: 2025-01-16 - Published: 2025-05-15 - Earliest claimed: 2017-01-11 - Assignees: InterDigital VC Holdings, Inc. - Applicants: Interdigital Vc Holdings, Inc. - Inventors: Fabrice URBAN; Tangi POIRIER; Fabrice LELEANNEC - Web page: https://patentgrep.com/patent/US20250159162A1 ## CPC - 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 19/122: Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type - 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 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/60: using transform coding - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract The present principles relates to a method and device 1. A method for encoding a residual block comprising: obtaining (500) a first coding mode relative to a first 2D transform when coding the residual blocks according a coding mode relative to a first 2D transform is enabled; obtaining (510) a second coding mode relative to a second 2D transform when coding the residual blocks according to a coding mode relative to a second 2D transform is enabled; and encoding (530) the residual block according to either said first coding mode or said second coding mode or both; the method is characterized in that enabling or disabling (520) the coding of the residual block according to said second coding mode depends on said first coding mode. The present principles relates also to a method and device for encoding/decoding a picture. ## Claims ### Claim 1 A method for encoding a residual block comprising: obtaining a first coding mode defining a 2D separable transform when coding the residual blocks according to a coding mode defining a 2D separable transform is enabled; obtaining a second coding mode defining a non-separable 2D transform when coding the residual blocks according to a coding mode defining a non-separable 2D transform is enabled; and encoding the residual block according to either said first coding mode or said second coding mode or both, wherein the method is characterized in that enabling or disabling the coding of the residual block according to said second coding mode depends on said first coding mode. ### Claim 2 A method for decoding a picture comprising: decoding a residual block by: obtaining a first coding mode defining a 2D separable transform when coding the residual blocks according to a coding mode defining a 2D separable transform is enabled; obtaining a second coding mode defining a non-separable 2D transform when coding the residual blocks according to a coding mode defining a non-separable 2D transform is enabled; and decoding the residual block according to either said first coding mode or said second coding mode or both, wherein the method is characterized in that enabling or disabling the coding of the residual block according to said second coding mode depends on said first coding mode. ### Claim 3 A device for encoding a residual block comprising means for: obtaining a first coding mode defining a separable 2D transform when coding the residual blocks according to a coding mode using a separable 2D transform is enabled; obtaining a second coding mode using a non-separable 2D transform when coding the residual blocks according to a coding mode defining a second 2D transform is enabled; and encoding the residual block according to either said first coding mode or said second coding mode or both, wherein the device is characterized in that enabling or disabling the coding of the residual block according to said second coding mode depends on said first coding mode. ### Claim 4 A device for decoding a picture comprising: a device for decoding a residual block comprising means for: obtaining a first coding mode defining a separable 2D transform when coding the residual blocks according to a coding mode using a separable 2D transform is enabled; obtaining a second coding mode using a non-separable 2D transform when coding the residual blocks according to a coding mode defining a second 2D transform is enabled; and decoding the residual block according to either the first coding mode or said second coding mode or both, wherein the device is characterized in that enabling or disabling the coding of the residual block according to the second coding mode depends on the first coding mode. ### Claim 5 A non-transitory storage medium carrying instructions of program code operative, when said program is executed on a computing device, to cause the computing device to: obtain a first coding mode defining a 2D separable transform when coding the residual blocks according to a coding mode defining a 2D separable transform is enabled; obtain a second coding mode defining a non-separable 2D transform when coding the residual blocks according to a coding mode defining a non-separable 2D transform is enabled; and decode the residual block according to either the first coding mode or the second coding mode or both, wherein enabling or disabling the coding of the residual block according to the second coding mode depends on said first coding mode. ### Claim 6 (depends on 1) The method of claim 1, wherein the coding of the residual block according to said second coding mode is enabled when the skip mode is disabled and when said first coding mode belongs to a predefined set of candidate coding modes. ### Claim 7 (depends on 1) The method of claim 1, wherein the coding of the residual block according to said second coding mode is enabled when the skip mode is disabled and when coding the residual blocks according to said first a coding mode is disabled. ### Claim 8 (depends on 1) The method of claim 1, wherein said second coding mode is obtained from a set of candidate coding modes and/or the cardinality and at least one of the candidate coding modes of said set of candidate coding modes are defined according to said first coding mode and/or whether coding the residual blocks according to said second coding mode enabled or disabled. ### Claim 9 (depends on 3) The device of claim 3, wherein the coding of the residual block according to the second coding mode is enabled when the skip mode is disabled and when the first coding mode belongs to a predefined set of candidate coding modes. ### Claim 10 (depends on 3) The device of claim 3, wherein the coding of the residual block according to the second coding mode is enabled when the skip mode is disabled and when coding the residual blocks according to the first a coding mode is disabled. ### Claim 11 (depends on 3) The device of claim 3, wherein the second coding mode is obtained from a set of candidate coding modes and/or the cardinality and at least one of the candidate coding modes of the set of candidate coding modes are defined according to the first coding mode and/or whether coding the residual blocks according to the second coding mode enabled or disabled.