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EP-4738815-A1 - TRANSFORM DERIVATION USING DIMD FOR TIMD/DIMD MODE

EP4738815A1EP 4738815 A1EP4738815 A1EP 4738815A1EP-4738815-A1

Abstract

Systems, methods, and instrumentalities are configured for transform derivation using decoder-side intra mode derivation (DIMD) for one or more of template-based intra mode derivation (TIMD) mode or DIMD mode. In examples, a video coding device may be configured to determine that a template-based intra mode derivation (TIMD) mode is enabled for a current block. The device may apply a decoder side intra mode derivation (DIMD) like process to derive a virtual intra prediction mode (VIPM) from a neighboring reconstructed template of a current block or a prediction block associated with the current block. The device may, based on the derived VIPM, determine a transform kernel set for predicted residual coding.

Inventors

  • PURI, Saurabh
  • BONNINEAU, Charles
  • UTIDA BARBOSA FERREIRA, Renan
  • NASER, Karam

Assignees

  • InterDigital CE Patent Holdings, SAS

Dates

Publication Date
20260506
Application Date
20241220

Claims (14)

  1. A video coding device comprising: a processor configured to: determine that a template-based intra mode derivation (TIMD) mode is enabled for a current block; apply a decoder side intra mode derivation (DIMD) like process to derive a virtual intra prediction mode (VIPM) from a neighboring reconstructed template of the current block or a prediction block associated with the current block; and based on the derived VIPM, determine a transform kernel set for predicted residual coding.
  2. The video coding device of claim 1, wherein: on a condition that the processor is configured to apply the DIMD like process to the neighboring reconstructed template, the processor is further configured to apply the DIMD like process when the TIMD mode and a TIMD blending mode are enabled; and on a condition that the processor is configured to apply the DIMD like process to the prediction block, the processor is further configured to apply the DIMD like process when a DIMD blending mode is enabled or the TIMD mode and a TIMD blending mode are enabled .
  3. The video coding device of claim 1 or claim 2, wherein the processor is further configured to determine that matrix-based position dependent prediction (PDP) is enabled for the current block.
  4. The video coding device of any of claims 1-3, wherein the transform kernel set is one of a multi-transform selection (MTS), a low frequency non-separable transform (LFNST), or a non-separable primary transform (NSPT).
  5. The video coding device of any of claim 1, claim 3, or claim 4, wherein the processor being configured to derive the VIPM comprises the processor being configured to derive the VIPM when a TIMD mode or a DIMD mode is blended with a BV-based predictor.
  6. The video coding device of claim 1, wherein the VIPM is a first VIPM and the current block is a TIMD block, and wherein the processor is configured to: derive the first VIPM using a first bin of a histogram of gradients (HoGs) computed on the prediction block; derive a second VIPM using a second bin of the HoGs on the prediction block; based on the first VIPM, determine a first transform kernel set; based on the second VIPM, determine a second transform kernel set; and test the first transform kernel set and the second transform kernel set to select one of the first transform kernel set or the second transform kernel set.
  7. The video coding device of claim 6, wherein the VIPM derived to obtain the transform kernel set is one of a multi-transform selection (MTS), a low frequency non-separable transform (LFNST), or a non-separable primary transform (NSPT).
  8. A method for video coding, wherein the method comprises: determining that a template-based intra mode derivation (TIMD) mode is enabled for a current block; applying a decoder side intra mode derivation (DIMD) like process to derive a virtual intra prediction mode (VIPM) from a neighboring reconstructed template of a current block or a prediction block associated with the current block; and based on the derived VIPM, determining a transform kernel set for predicted residual coding.
  9. The method of claim 8, wherein the method further comprises: on a condition that the DIMD like process is applied to the neighboring reconstructed template, the method further comprises applying the DIMD like process when the TIMD mode and a TIMD blending mode are enabled; and on a condition that the DIMD like process is applied to the prediction block, the method further comprises applying the DIMD like process when a DIMD blending mode is enabled or the TIMD mode and a TIMD blending mode are enabled.
  10. The method of any of claims 8 or 9, wherein the method further comprises determining that matrix-based position dependent prediction (PDP) is enabled for the current block.
  11. The method of any of claims 8-10, wherein the transform kernel set is one of a multi-transform selection (MTS), a low frequency non-separable transform (LFNST), or a non-separable primary transform (NSPT).
  12. The method of any of claims 8, 10, 11, wherein deriving the VIPM comprises deriving the VIPM when a TIMD mode or a DIMD mode is blended with a BV-based predictor.
  13. The method of claim 8, wherein the VIPM is a first VIPM and the current block is a TIMD block, and the method further comprises: deriving the first VIPM using a first bin of a histogram of gradients (HoGs) computed on the prediction block; deriving a second VIPM using a second bin of the HoGs on the prediction block; based on the first VIPM, determining a first transform kernel set; based on the second VIPM, determining a second transform kernel set; and testing the first transform kernel set and the second transform kernel set to select one of the first transform kernel set or the second transform kernel set.
  14. The method of claim 13, wherein the VIPM derived to obtain the transform kernel set is one of a multi-transform selection (MTS), a low frequency non-separable transform (LFNST), or a non-separable primary transform (NSPT).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of EP provisional patent application No. 24306846.7, filed October 31, 2024, the disclosure of which is incorporated herein by reference in its entirety. BACKGROUND The present application is related to video coding systems that 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 Systems, methods, and instrumentalities are configured for transform derivation using decoder-side intra mode derivation (DIMD) for one or more of template-based intra mode derivation (TIMD) mode or DIMD mode. In examples, a video coding device may be configured to determine that a template-based intra mode derivation (TIMD) mode is enabled for a current block. The device may apply a decoder side intra mode derivation (DIMD) like process to derive a virtual intra prediction mode (VIPM) from a neighboring reconstructed template of the current block or a prediction block associated with the current block. The device may, based on the derived VIPM, determine a transform kernel set for predicted residual coding. The device may, on a condition that the processor is configured to apply the DIMD like process to the neighboring reconstructed template, apply the DIMD like process when the TIMD mode and a TIMD blending mode are enabled. The device may, on a condition that the processor is configured to apply the DIMD like process to the prediction block, apply the DIMD like process when a DIMD blending mode is enabled or the TIMD mode and a TIMD blending mode are enabled . The device may determine that matrix-based position dependent prediction (PDP) is enabled for the current block. The transform kernel set may be one of a multi-transform selection (MTS), a low frequency non-separable transform (LFNST), or a non-separable primary transform (NSPT). Deriving the VIPM may include deriving the VIPM when a TIMD mode or a DIMD mode is blended with a BV-based predictor. The VIPM may be a first VIPM and the current block may be a TIMD block. The device may derive the first VIPM using a first bin of a histogram of gradients (HoGs) computed on the prediction block. The device may derive a second VIPM using a second bin of the HoGs on the prediction block. Thedevice may, based on the first VIPM, determine a first transform kernel set. The device may, based on the second VIPM, determine a second transform kernel set. The device may test the first transform kernel set and the second transform kernel set to select one of the first transform kernel set or the second transform kernel set. The VIPM derived to obtain the transform kernel set may be one of a multi-transform selection (MTS), a low frequency non-separable transform (LFNST), or a non-separable primary transform (NSPT). A video coding device may be configured to apply decoder-side intra mode derivation (DIMD) to a neighboring reconstructed template associated with a current block to derive a virtual intra prediction mode (VIPM) associated with the current block. The device may, based on the derived VIPM, determine a transform kernel set for predicted residual coding. The device may derive the VIPM on predicted samples of the current block. The transform kernel set may be associated with multi-transform selection (MTS) or at least one of a low frequency non-separable transform (LFNST) or a non-separable primary transform (NSPT). The device may determine that a TIMD blending mode is enabled. The device may determine that a TIMD mode and a TIMD blending mode is enabled. The device may determine that a TIMD is blended with a BV-based predictor. The coding device may include a video decoding device. The coding device may include a video encoding device. BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description will be better understood when read in conjunction with the appended drawings, in which there are shown examples of one or more of the multiple embodiments of the present disclosure. It should be understood, however, that the embodiments described herein are not limited to the precise arrangements and instrumentalities shown in the drawings. FIG. 1 shows an example system according to one or more embodiments of the present disclosure.FIG. 2 shows an example video encoder according to one or more embodiments of the present disclosure.FIG. 3 shows an example video decoder according to one or more embodiments of the present disclosure.FIG. 4 shows an example decoder side intra mode derivation (DIMD) template to form a histogram of gradients (HoG).FIG. 5 illustrates an example position dependent prediction (PDP) (left) and PDP for template cost calculation in template-based intra mode derivation (TIMD) (right).FIG. 6 shows an example of four reference lines neighboring to a prediction block.FIG. 7 shows an example of an extende