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JP-7856834-B2 - Image encoding/decoding method, apparatus, and bitstream transmission method using BDPCM

JP7856834B2JP 7856834 B2JP7856834 B2JP 7856834B2JP-7856834-B2

Inventors

  • ユ ソンミ
  • ホ チン
  • チェ チャンウォン
  • チェ チョン ア

Assignees

  • オッポ広東移動通信有限公司

Dates

Publication Date
20260511
Application Date
20250812
Priority Date
20190417

Claims (20)

  1. An image decoding method performed by an image decoding device, Currently, the question is whether BDPCM (block difference pulse code modulation) is applied to the block, When the BDPCM is applied to the current block, the prediction direction of the BDPCM for the current block is determined, Based on the prediction direction of the BDPCM for the current block, the intra-prediction mode of the current block is determined, Based on the predicted direction of the BDPCM, a residual block of the current block is generated, Based on the intra-prediction mode of the current block, an intra-prediction is performed to generate a predicted block for the current block, Reconstructing the current block based on the residual block and the predicted block, Includes, Determining whether the BDPCM is applied to the current block is: An image decoding method characterized by including parsing a bitstream for first information that indicates only that the BDPCM should be applied to the chroma component of the current block.
  2. Determining the prediction direction of the BDPCM for the current block is: The image decoding method according to claim 1, characterized by comprising parsing a second information from a bitstream that indicates the prediction direction of the BDPCM for the current block.
  3. The image decoding method according to claim 1, characterized in that the prediction direction of the BDPCM for the current block includes the horizontal or vertical direction.
  4. Determining the intra-prediction mode of the current block based on the prediction direction of the BDPCM for the current block is: When the prediction direction of the BDPCM is horizontal, the intra-prediction mode of the current block is determined to be the horizontal mode. When the prediction direction of the BDPCM is vertical, the intra-prediction mode of the current block is determined to be the vertical mode. The image decoding method according to claim 1, characterized by including the following.
  5. The aforementioned image decoding method is The image decoding method according to claim 1, further comprising determining an intra-prediction mode for the current block based on prediction information for the current block signaled via a bitstream, if the BDPCM is not applied to the current block.
  6. An image encoding method performed by an image encoding device, Currently, the question is whether BDPCM (block difference pulse code modulation) is applied to the block, When the BDPCM is applied to the current block, the prediction direction of the BDPCM for the current block is determined, Based on the prediction direction of the BDPCM for the current block, the intra-prediction mode of the current block is determined, The prediction block of the current block is generated by performing intra-prediction based on the intra-prediction mode of the current block, Based on the predicted block, generate the current block's residual block, Based on the prediction direction of the BDPCM, the current block's residual block is encoded, Includes, The aforementioned image encoding method is An image encoding method characterized by further comprising encoding first information that indicates only that the BDPCM is applied to the chroma component of the current block.
  7. The image coding method according to claim 6, further comprising encoding second information indicating the predicted direction of the BDPCM for the current block.
  8. The image encoding method according to claim 6, characterized in that the prediction direction of the BDPCM for the current block includes the horizontal or vertical direction.
  9. Determining the intra-prediction mode of the current block based on the prediction direction of the BDPCM for the current block is: When the prediction direction of the BDPCM is horizontal, the intra-prediction mode of the current block is determined to be the horizontal mode. When the prediction direction of the BDPCM is vertical, the intra-prediction mode of the current block is determined to be the vertical mode. The image coding method according to claim 6, which includes the following:
  10. An image decoding device, Includes memory and at least one processor, The at least one processor is Currently, we determine whether BDPCM (block difference pulse code modulation) is applied to the block. When the BDPCM is applied to the current block, the prediction direction of the BDPCM for the current block is determined. Based on the prediction direction of the BDPCM for the current block, the intra-prediction mode of the current block is determined. Based on the predicted direction of the BDPCM, a residual block of the current block is generated. A prediction block for the current block is generated by performing an intra-prediction based on the intra-prediction mode of the current block. The current block is reconstructed based on the residual block and the predicted block. The at least one processor determines whether the BDPCM is applied to the current block. An image decoding apparatus characterized by including parsing from a bitstream first information that indicates only that the BDPCM should be applied to the chroma component of the current block.
  11. The at least one processor determines the prediction direction of the BDPCM for the current block, The image decoding apparatus according to claim 10, characterized in that it includes parsing from a bitstream second information indicating the prediction direction of the BDPCM for the current block.
  12. The image decoding apparatus according to claim 10, characterized in that the prediction direction of the BDPCM for the current block includes the horizontal or vertical direction.
  13. The at least one processor determines the intra-prediction mode of the current block based on the prediction direction of the BDPCM for the current block, If the prediction direction of the BDPCM is horizontal, the intra-prediction mode of the current block is determined to be the horizontal mode. If the prediction direction of the BDPCM is vertical, the intra-prediction mode of the current block is determined to be the vertical mode. The image decoding apparatus according to claim 10, characterized by including the following.
  14. The image decoding apparatus according to claim 10, further comprising the at least one processor, which, when the BDPCM is not applied to the current block, determines the intra-prediction mode of the current block based on prediction information of the current block signaled via the bitstream.
  15. An image encoding device, Includes memory and at least one processor, The at least one processor is Currently, we determine whether BDPCM (block difference pulse code modulation) is applied to the block. When the BDPCM is applied to the current block, the prediction direction of the BDPCM for the current block is determined. Based on the prediction direction of the BDPCM for the current block, the intra-prediction mode of the current block is determined. A prediction block for the current block is generated by performing an intra-prediction based on the intra-prediction mode of the current block. Based on the predicted block, generate the current block's residual block, Based on the predicted direction of the BDPCM, the current block's residual block is encoded. The image encoding device is characterized in that at least one processor further encodes first information indicating only that the BDPCM is applied to the chroma component of the current block.
  16. The image encoding apparatus according to claim 15, further comprising at least one processor encoding second information indicating the prediction direction of the BDPCM for the current block.
  17. The image encoding apparatus according to claim 15, characterized in that the prediction direction of the BDPCM for the current block includes the horizontal or vertical direction.
  18. The at least one processor determines the intra-prediction mode of the current block based on the prediction direction of the BDPCM for the current block. If the prediction direction of the BDPCM is horizontal, the intra-prediction mode of the current block is determined to be the horizontal mode. If the prediction direction of the BDPCM is vertical, the intra-prediction mode of the current block is determined to be the vertical mode. The image encoding apparatus according to claim 15, characterized by including the following.
  19. A method for transmitting a bitstream, A bitstream is generated by performing the image encoding method described in claim 6, Transmitting the aforementioned bitstream, A method for transmitting a bitstream that includes [a specific element].
  20. A computer-readable storage medium, The computer-readable storage medium stores a computer program and a bitstream, and when the computer program is executed by a processor, the steps of the image encoding method described in claim 6 are realized to generate a bitstream. A computer-readable storage medium characterized by the following features.

Description

This disclosure relates to an image encoding/decoding method and apparatus, and more particularly to a method and apparatus for encoding/decoding images using BDPCM (block difference pulse code modulation), and a method for transmitting a bitstream generated by the image encoding method/apparatus of this disclosure. Recently, the demand for high-resolution, high-quality images, such as HD (High Definition) and UHD (Ultra High Definition) images, has been increasing in various fields. As image data becomes higher resolution and higher quality, the amount of information or bits transmitted increases relatively compared to conventional image data. This increase in the amount of information or bits transmitted leads to increased transmission and storage costs. This necessitates highly efficient image compression technology for effectively transmitting, storing, and reproducing high-resolution, high-quality image information. This figure schematically illustrates a video coding system to which the embodiments described herein can be applied.This figure schematically shows an image encoding device to which the embodiments of this disclosure can be applied.This figure schematically shows an image decoding apparatus to which the embodiments of this disclosure can be applied.This is a schematic flowchart of an image decoding procedure to which the embodiments described herein can be applied.This is a schematic flowchart of an image coding procedure to which the embodiments disclosed herein can be applied.This flowchart shows an intra-predictive-based video/image encoding method.This figure illustrates the configuration of the intra prediction unit 185 according to this disclosure.This flowchart shows an intra-predictive-based video/image decoding method.This figure illustrates the configuration of the intra prediction unit 265 according to this disclosure.This figure shows the intra-prediction direction according to one embodiment of the present disclosure.This figure shows the intra-prediction direction according to another embodiment of the present disclosure.This figure illustrates the method for encoding residual samples of BDPCM according to this disclosure.This figure shows a modified quantized resistive block generated by performing the BDPCM of this disclosure.This flowchart shows the procedure for encoding the current block using BDPCM in an image encoding device.This flowchart shows the procedure for restoring the current block by applying BDPCM to an image decoding device.This diagram provides a schematic overview of the BDPCM information currently included in the block's syntax structure.This is a flowchart illustrating a method for encoding/decoding BDPCM-related information according to one embodiment of the present disclosure.This is a flowchart illustrating a method for guiding the prediction direction of a BDPCM based on the intra-prediction direction of the current block according to other embodiments of the present disclosure.This is a flowchart illustrating a method for inducing an intra-prediction mode of the current block based on the prediction direction of the BDPCM according to another embodiment of the present disclosure.This is a flowchart illustrating a method for guiding the prediction direction of the BDPCM based on the current block size according to another embodiment of the present disclosure.This is a diagram illustrating the CABAC entropy coding method.This figure illustrates a template for a block to which BDPCM is applied according to one embodiment of the present disclosure.This figure illustrates a template for a block to which BDPCM is applied according to one embodiment of the present disclosure.This disclosure provides a flowchart illustrating a method for defining a template considering the prediction direction of BDPCM and deriving a context model or Rice parameters.This figure illustrates a template for a block to which BDPCM has been applied, according to other embodiments of the present disclosure.This figure illustrates a template for a block to which BDPCM has been applied, according to other embodiments of the present disclosure.This disclosure provides a flowchart illustrating how to define a template considering the BDPCM lines and how to derive a context model or Rice parameters.This figure illustrates a template for a block to which BDPCM is applied, according to another embodiment of the present disclosure.This figure illustrates a template for a block to which BDPCM is applied, according to another embodiment of the present disclosure.This disclosure provides a flowchart illustrating how to define a template and derive a context model or Rice parameter by considering whether or not peripheral pixels are included in the first line of the BDPCM.This figure illustrates a template for a block to which BDPCM is applied, according to another embodiment of the present disclosure.This figure illustrates a template for a block to which BDPCM is applied, according to ano