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EP-4736420-A1 - BLOCK VECTOR GUIDED CHROMA DIRECT MODE

EP4736420A1EP 4736420 A1EP4736420 A1EP 4736420A1EP-4736420-A1

Abstract

An apparatus, which may be, for example, an encoder or decoder, may be configured to determine direct mode (DM) prediction applies to a first chroma block. The apparatus determines for the first chroma block that an associated first luma block is coded with one of intra block copy (IBC) or Intra template matching (IntraTMP). The apparatus determines a reference block associated with the first luma block and Intra information associated with the reference block. The reference block associated with the first luma block may have been used for processing the first luma block. The apparatus determines vectors associated with the first luma block and determines, based on the vectors, the reference block and Intra information associated with the reference block. The apparatus determines a first intra mode associated with the reference block and performs prediction for the first chroma block using the first intra mode associated with the reference block.

Inventors

  • NASER, Karam
  • BORDES, PHILIPPE
  • CHEN, Ya
  • RATH, Gagan Bihari

Assignees

  • InterDigital CE Patent Holdings, SAS

Dates

Publication Date
20260506
Application Date
20240624

Claims (15)

  1. 1. A device for decoding comprising: a processor configured to: determine direct mode (DM) prediction applies to a chroma block; determine that a collocated luma block is coded using a block vector-based prediction mode; identify a reference block associated with the collocated luma block; determine a prediction mode associated with the reference block; and decode the chroma block based on at least the determined prediction mode associated with the reference block.
  2. 2. A device for encoding comprising: a processor configured to: determine direct mode (DM) prediction applies to a chroma block; determine that a collocated luma block is coded using a block vector-based prediction mode; identify a reference block associated with the collocated luma block; determine a prediction mode associated with the reference block; and encode the chroma block based on at least the determined prediction mode associated with the reference block.
  3. 3. The device of claim 1 , wherein the processor is further configured to: identify a second reference block associated with the collocated luma block; determine a second prediction mode associated with the second reference block, wherein the processor configured to decode the chroma block based on at least the determined prediction mode associated with the reference block is further configured to decode the chroma block based on at least the determined prediction mode associated with the reference block and the second prediction mode associated with the second reference block.
  4. 4. The device of claim 1 or 2, wherein the processor configured to determine that the collocated luma block is coded using the block vector-based prediction mode is further configured to determine that the collocated luma block is coded using one of an intra-block copy (IBC) or Intra template matching (IntraTMP).
  5. 5. The device of claim 1 or 2, wherein the reference block associated with the collocated luma block is used for processing the collocated luma block.
  6. 6. The device of claim 1 or 2, wherein the processor configured to identify the reference block associated with the collocated luma block is further configured to: determine vectors associated with the collocated luma block; and identify, based on the vectors, the reference block associated with the collocated luma block.
  7. 7. The device of claim 6, wherein the processor configured to determine vectors associated with the collocated luma block is further configured to determine a plurality of reference blocks and determine a respective vector for each of a plurality of reference blocks.
  8. 8. The device of claim 1 or 2, wherein the processor is further configured to: determine, for a second chroma block, an associated second luma block is not coded with a block-based prediction mode; determine a second prediction mode associated with the second luma block; and perform prediction for the second chroma block using the second prediction mode.
  9. 9. A method of decoding comprising: determining direct mode (DM) prediction applies to a chroma block; determining that a collocated luma block is coded using a block vector-based prediction mode; identifying a reference block associated with the collocated luma block; determining a prediction mode associated with the reference block; and decoding the chroma block based on at least the determined prediction mode associated with the reference block.
  10. 10. A method of encoding comprising: determining direct mode (DM) prediction applies to a chroma block; determining that a collocated luma block is coded using a block vector-based prediction mode; identifying a reference block associated with the collocated luma block; determining a prediction mode associated with the reference block; and encoding the chroma block based on at least the determined prediction mode associated with the reference block.
  11. 1 1 . The method of claim 9 or 10, further comprising: identifying a second reference block associated with the collocated luma block; and determining a second prediction mode associated with the second reference block, wherein decoding the chroma block based on at least the determined prediction mode associated with the reference block comprises decoding the chroma block based on at least the determined prediction mode associated with the reference block and the second prediction mode associated with the second reference block.
  12. 12. The method of claim 9 or 10, wherein determining that the collocated luma block is coded using the block vectorbased prediction mode further comprises determining that the collocated luma block is coded using one of an intra-block copy (IBC) or Intra template matching (IntraTMP).
  13. 13. The method of claim 9 or 10, wherein the reference block associated with the collocated luma block is used for processing the collocated luma block.
  14. 14. The method of claim 9 or 10, wherein identifying the reference block associated with the collocated luma block further comprises: determining vectors associated with the collocated luma block; and identifying, based on the vectors, the reference block associated with the collocated luma block.
  15. 15. A computer program product stored on a computer readable medium and comprising program code instructions for implementing the steps of a method according to any of claims 9 through 14 when executed by a processor.

Description

BLOCK VECTOR GUIDED CHROMA DIRECT MODE CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of European Patent Application Number 23306108.4, filed June 30, 2023, the contents of which are hereby incorporated by reference herein in their entirety. BACKGROUND [0002] Video coding systems may be used to compress digital video signals, e.g., to reduce the storage and/or transmission bandwidth needed for such signals. Video coding systems may include, for example, block-based, wavelet-based, and/or object-based systems. SUMMARY [0003] Systems, methods, and instrumentalities are disclosed for performing guided chroma direct mode. [0004] A device which may be, for example, a video decoder device and/or video encoder device, may be configured to determine direct mode (DM) prediction applies to a chroma block. The device may determine that a collocated luma block is coded using a block vectorbased prediction mode. For example, the device may be configured to determine that the collocated luma block is coded using one of an intra-block copy (IBC) or Intra template matching (IntraTMP). [0005] The device may identify a reference block associated with the collocated luma block. For example, the device may determine vectors associated with the collocated luma block, and may identify, based on the vectors, the reference block associated with the collocated luma block. The device may determine a plurality of reference blocks and determine a respective vector for each of a plurality of reference blocks. The reference block associated with the collocated luma block may be used for processing the collocated luma block. [0006] The device may determine a prediction mode associated with the reference block. The device may decode or encode the chroma block based on at least the determined prediction mode associated with the reference block. [0007] The device may identify a second reference block associated with the collocated luma block and may determine a second prediction mode associated with the second reference block. The device may decode or encode the chroma block based on at least the determined prediction mode associated with the reference block and the second prediction mode associated with the second reference block. [0008] An apparatus, which may be, for example, an encoder or decoder, may be configured to determine direct mode (DM) prediction applies to a first chroma block. The apparatus may determine for the first chroma block that an associated first luma block is coded with one of intra block copy (IBC) or Intra template matching (IntraTMP). The apparatus may determine a reference block associated with the first luma block and Intra information associated with the reference block. The reference block associated with the first luma block may have been used for processing the first luma block. The apparatus may determine vectors associated with the first luma block and may determine, based on the vectors, the reference block and Intra information associated with the reference block. [0009] The apparatus may determine a first intra mode associated with the reference block and may perform prediction for the first chroma block using the first intra mode associated with the reference block. [0010] The apparatus may determine for a second chroma block that an associated second luma block is not coded with IBC or IntraTMP. The apparatus may determine a second intra mode associated with the second luma block and may perform prediction for the second chroma block using the second intra mode. [0011] Systems, methods, and instrumentalities described herein may involve a decoder. In some examples, the systems, methods, and instrumentalities described herein may involve an encoder. In some examples, the systems, methods, and instrumentalities described herein may involve a signal (e.g., from an encoder and/or received by a decoder). A computer- readable medium may include instructions for causing one or more processors to perform methods described herein. A computer program product may include instructions which, when the program is executed by one or more processors, may cause the one or more processors to carry out the methods described herein. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented. [0013] FIG. 1 B is a system diagram illustrating an example wireless transmit/receive unit (WTRLI) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment. [0014] FIG. 1 C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment. [0015] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in