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CN-122003861-A - Coding tree cell grid shifting

CN122003861ACN 122003861 ACN122003861 ACN 122003861ACN-122003861-A

Abstract

Systems, methods, and tools may perform CTU grid shifting. In an example, a device may include a processor. The apparatus may be configured to obtain a picture comprising a plurality of Coding Tree Units (CTUs). The device may select CTU grid shift values based on the associated feature values. The CTU grid shift value may be selected from a plurality of CTU grid shift values. In an example, each CTU grid shift value from the plurality of CTU grid shift values may be associated with a respective feature value. The device may encode the picture based on the selected CTU grid shift value. In an example, the associated feature value may indicate at least one of an activity value, a block boundary activity of a block, one or more spatial gradients, or a number of blocks associated with Intra Block Copy (IBC).

Inventors

  • E. FRANCOIS
  • T. Prue
  • F. Leonek
  • F. Garr Ping

Assignees

  • 交互数字CE专利控股有限公司

Dates

Publication Date
20260508
Application Date
20240806
Priority Date
20230817

Claims (15)

  1. 1. A video encoding apparatus comprising: A processor configured to: Obtaining a picture comprising a plurality of Coding Tree Units (CTUs); Selecting a CTU grid shift value based on the associated feature values, wherein the CTU grid shift value is selected from a plurality of CTU grid shift values, and wherein each CTU grid shift value from the plurality of CTU grid shift values is associated with a respective feature value, and The picture is encoded based on the selected CTU grid shift value.
  2. 2. The video encoding device of claim 1, wherein the characteristic value associated with the selected CTU grid shift value indicates a block boundary activity of a block of the plurality of CTUs that is shifted based on the CTU grid shift value.
  3. 3. The video encoding device of claim 1, wherein the eigenvalues associated with the selected CTU grid shift values indicate one or more spatial gradients of samples of the plurality of CTUs shifted based on the CTU grid shift values, and wherein the one or more spatial gradients are determined by applying a high pass filter to samples of the plurality of CTUs.
  4. 4. The video encoding device of claim 1, wherein the characteristic value associated with the selected CTU grid shift value indicates a number of blocks of the plurality of CTUs that are shifted based on the CTU grid shift value, wherein the number of blocks is associated with an Intra Block Copy (IBC) prediction mode.
  5. 5. The video encoding device of any one of claims 1-4, wherein feature values associated with the selected CTU grid shift values are derived for a first block size and for a second block size, wherein the first block size is larger than the second block size.
  6. 6. The video encoding device of any one of claims 1-5, wherein the processor is further configured to: Determining a subsampled search space for the plurality of CTU grid shift values, and The CTU grid shift value is further selected based on the subsampled search space.
  7. 7. The video encoding device of claims 1-6, wherein the selected CTU grid shift value is signaled in the video data.
  8. 8. A video encoding method, comprising: Obtaining a picture comprising a plurality of Coding Tree Units (CTUs); Selecting a CTU grid shift value based on the associated feature values, wherein the CTU grid shift value is selected from a plurality of CTU grid shift values, and wherein each CTU grid shift value from the plurality of CTU grid shift values is associated with a respective feature value, and The picture is encoded based on the selected CTU grid shift value.
  9. 9. The video encoding method of claim 8, wherein the characteristic value associated with the selected CTU grid shift value indicates a block boundary activity of a block of the plurality of CTUs that is shifted based on the CTU grid shift value.
  10. 10. The video encoding method of claim 8, wherein the eigenvalues associated with the selected CTU grid shift values indicate one or more spatial gradients of samples of the plurality of CTUs shifted based on the CTU grid shift values, and wherein the one or more spatial gradients are determined by applying a high pass filter to samples of the plurality of CTUs.
  11. 11. The video encoding method of claim 8, wherein the characteristic value associated with the selected CTU grid shift value indicates a number of blocks of the plurality of CTUs that are shifted based on the CTU grid shift value, wherein the number of blocks is associated with an Intra Block Copy (IBC) prediction mode.
  12. 12. The video encoding method of any one of claims 8-11, wherein feature values associated with the selected CTU grid shift values are derived for a first block size and for a second block size, wherein the first block size is larger than the second block size.
  13. 13. The video coding method of any of claims 8-12, wherein the method further comprises: a sub-sample search space of the plurality of CTU grid shift values is determined, wherein the CTU grid shift values are further selected based on the sub-sample search region.
  14. 14. The video coding method of any of claims 8-13, wherein the selected CTU grid shift values are signaled in video data.
  15. 15. A computer program product stored on a non-transitory computer readable medium and comprising program code instructions for implementing the steps of the method according to at least one of claims 8-14 when executed by a processor.

Description

Coding tree cell grid shifting Cross Reference to Related Applications The present application claims the benefit of european provisional patent application No. 23306389.0 filed 8/17 in 2023, the contents of which are hereby incorporated by reference. Background Video codec systems may be used to compress digital video signals, for example, to reduce the storage and/or transmission bandwidth required for such signals. Video codec systems may include, for example, block-based, wavelet-based, and/or object-based systems. Disclosure of Invention Systems, methods, and tools are disclosed for performing CTU grid shifting, e.g., based on feature values associated with pictures. A device, which may be, for example, an encoder, may obtain a picture comprising a plurality of Coding Tree Units (CTUs). The device may select CTU grid shift values from a plurality of CTU grid shift values, e.g., based on their respective associated characteristic values. The device may encode the picture based on the selected CTU grid shift value. Example eigenvalues associated with CTU grid shift values may indicate spatial gradients in CTUs of samples shifted based on CTU grid shift values. Example feature values associated with CTU grid shift values may indicate block boundary activities of blocks in the CTU that are shifted based on the CTU grid shift values. The example feature values associated with the CTU grid shift values may indicate a number of blocks in the CTU that are suitable for the intra block copy prediction mode that are shifted based on the CTU grid shift values. The video encoding device may include a processor. The apparatus may be configured to obtain a picture comprising a plurality of Coding Tree Units (CTUs). The device may be configured to select CTU grid shift values based on the associated feature values. The CTU grid shift value may be selected from a plurality of CTU grid shift values. Each CTU grid shift value from the plurality of CTU grid shift values may be associated with a respective characteristic value. The device may be configured to encode the picture based on the selected CTU grid shift value. The characteristic value associated with the selected CTU grid shift value may indicate a block boundary activity of a block of the plurality of CTUs shifted based on the CTU grid shift value, one or more spatial gradients of samples of the plurality of CTUs shifted based on the CTU grid shift value, and/or a number of blocks of the plurality of CTUs shifted based on the CTU grid shift value. The one or more spatial gradients may be determined by applying a high pass filter to samples in the plurality of CTUs. The number of blocks may be associated with an Intra Block Copy (IBC) prediction mode. The eigenvalues associated with the selected CTU grid shift values may be derived for the first block size and/or for the second block size. The first block size may be larger than the second block size. The apparatus may be configured to determine a subsampled search space of a plurality of CTU grid shift values. The device may be configured to select CTU grid shift values further based on the subsampled search space. The selected grid shift value may be signaled in the video data. A video encoding method may include obtaining a picture including a plurality of Coding Tree Units (CTUs). The method may include selecting CTU grid shift values based on the associated feature values. The CTU grid shift value may be selected from a plurality of CTU grid shift values. Each CTU grid shift value from the plurality of CTU grid shift values may be associated with a respective characteristic value. The method may include encoding a picture based on the selected CTU grid shift value. The characteristic value associated with the selected CTU grid shift value may indicate a block boundary activity of a block of the plurality of CTUs shifted based on the CTU grid shift value, one or more spatial gradients of samples of the plurality of CTUs shifted based on the CTU grid shift value, and/or a number of blocks of the plurality of CTUs shifted based on the CTU grid shift value. The one or more spatial gradients may be determined by applying a high pass filter to samples in the plurality of CTUs. The number of blocks may be associated with an Intra Block Copy (IBC) prediction mode. The eigenvalues associated with the selected CTU grid shift values may be derived for the first block size and/or for the second block size. The first block size may be larger than the second block size. The method may include determining a subsampled search space of a plurality of CTU grid shift values. The CTU grid shift value may be further selected based on the subsampled search space. The selected CTU grid shift value may be signaled in the video data. A computer program product stored on a non-transitory computer readable medium may comprise program code instructions for implementing the steps of the method as described herein when executed by a pro