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CN-120091135-B - Intra-frame prediction method and device

CN120091135BCN 120091135 BCN120091135 BCN 120091135BCN-120091135-B

Abstract

The application provides an intra prediction method and device for reconstructing unavailable reference samples. The method comprises the steps of obtaining an intra-frame prediction mode of a current block, obtaining availability of reference samples of components of the current block, replacing unavailable reference samples with available reference samples, obtaining prediction of the current block according to the intra-frame prediction mode and the replaced reference samples, and reconstructing the current block according to the prediction. The components include Cb components or Cr components. Or the component may comprise a chrominance component. Since the method obtains the availability of the reference sample in each component, the available information can be provided more accurately.

Inventors

  • MA XIANG
  • YANG HAITAO
  • CHEN JIANLE

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260505
Application Date
20191121
Priority Date
20181121

Claims (20)

  1. 1. An image intra prediction apparatus, comprising: a memory, the memory comprising instructions; one or more processors in communication with the memory, wherein the one or more processors execute the instructions to: Acquiring an intra-frame prediction mode of a current block; obtaining availability availableN of reference samples of a cIdx component of the current block, wherein cIdx values are 0,1 and 2,0 indicating a luma component, 1 and 2 indicating a chroma component, and availableN value is false when the isacable [ cIdx ] [ x ] [ y ] value is false, wherein isacable [ cIdx ] [ x ] [ y ] is used to indicate available information of samples of each component cIdx at a sample position (x, y); Replacing the unavailable reference sample with the available reference sample; and obtaining the prediction of the current block according to the intra-frame prediction mode and the replaced reference sample.
  2. 2. The apparatus of claim 1, wherein the chroma component comprises a Cb component or a Cr component, the one or more processors executing the instructions to: obtaining availability of the reference sample by checking availability of Cb samples within a neighboring Cb block, wherein the neighboring Cb block includes the reference sample, or Availability of the reference samples is obtained by checking availability of Cr samples within neighboring Cr blocks, wherein the neighboring Cr blocks comprise the reference samples.
  3. 3. The apparatus of claim 1 or 2, wherein all Cb samples in the reconstructed block of the current block are marked as available or all Cr samples in the reconstructed block of the current block are marked as available.
  4. 4. The apparatus of claim 1 or 2, wherein the one or more processors execute the instructions to: obtaining the prediction of the current block by mapping the replaced reference samples to the current block according to the intra prediction mode; Reconstructing the current block by adding a residual to the prediction of the current block; After reconstructing the current block, marking all samples in a block area as available, wherein the block area is an area where the current block is located.
  5. 5. The apparatus of claim 4, wherein the block region comprises a plurality of cells, each cell having a cell region, all samples in the cell region being marked as available.
  6. 6. The apparatus of claim 5, wherein the device comprises a plurality of sensors, When the current block is a Cb block, all Cb samples at the location covered by the block area are marked as available, or When the current block is a Cr block, all Cr samples at the locations covered by the block area are marked as available.
  7. 7. The apparatus of any one of claims 1 to 2, 5 to 6, wherein the availability of reference samples for each component is preserved.
  8. 8. The apparatus according to any one of claims 1 to 2, 5 to 6, wherein the chrominance component consists of a Cb component and a Cr component, the Cb component and the Cr component sharing the same availability information.
  9. 9. A method of intra prediction of an image performed by an encoder or decoder, comprising: Acquiring an intra-frame prediction mode of a current block; obtaining availability availableN of reference samples of a cIdx component of the current block, wherein cIdx values are 0,1 and 2,0 indicating a luma component, 1 and 2 indicating a chroma component, and availableN value is false when the isacable [ cIdx ] [ x ] [ y ] value is false, wherein isacable [ cIdx ] [ x ] [ y ] is used to indicate available information of samples of each component cIdx at a sample position (x, y); Replacing the unavailable reference sample with the available reference sample; and obtaining the prediction of the current block according to the intra-frame prediction mode and the replaced reference sample.
  10. 10. The method of claim 9, wherein the chroma component comprises a Cb component or a Cr component: obtaining availability of the reference sample by checking availability of Cb samples within a neighboring Cb block, wherein the neighboring Cb block includes the reference sample, or Availability of the reference samples is obtained by checking availability of Cr samples within neighboring Cr blocks, wherein the neighboring Cr blocks comprise the reference samples.
  11. 11. The method according to claim 9 or 10, characterized in that all Cb samples in the reconstructed block of the current block are marked as available or all Cr samples in the reconstructed block of the current block are marked as available.
  12. 12. The method according to claim 9 or 10, characterized in that the method further comprises: Obtaining the prediction of the current block by mapping the replaced reference samples to the current block according to an intra prediction mode; Reconstructing the current block by adding a residual to the prediction of the current block; After reconstructing the current block, marking all samples in a block area as available, wherein the block area is an area where the current block is located.
  13. 13. The method of claim 12, wherein the block area comprises a plurality of cells, each cell having a cell area.
  14. 14. The method according to claim 13, wherein: When the current block is a Cb block, all Cb samples at the location covered by the block area are marked as available, or When the current block is a Cr block, all Cr samples at the locations covered by the block area are marked as available.
  15. 15. The method of claim 13, wherein in a cell N x1 or 1 x N, only right and bottom boundary samples are marked as available.
  16. 16. The method of claim 13, wherein in element N x N, only right and bottom boundary samples are marked as available.
  17. 17. The method according to any of claims 9 to 10, 13 to 16, characterized in that the availability of reference samples for each component is preserved.
  18. 18. The method of claim 9, wherein the chroma components consist of a Cb component and a Cr component that share the same availability information.
  19. 19. The method of claim 12, wherein after reconstructing a cell in the current block, all samples in a cell region of the cell are marked as available.
  20. 20. The method of claim 12, wherein samples at a right boundary and a bottom boundary of the current block are marked as available after reconstructing the current block.

Description

Intra-frame prediction method and device The present application is a divisional application, the application number of the original application is 201980069241.2, the original application date is 11 months 21 in 2019, and the whole content of the original application is incorporated by reference into the present application. Cross-reference to related application The present application claims priority from U.S. provisional patent application No. 62/770,736, entitled "intra prediction method and apparatus (Intra Prediction Method AND DEVICE)" filed on 11/21 2018, the disclosure of which is incorporated herein by reference. Technical Field Embodiments of the present invention relate generally to the field of video coding, and more particularly, to the field of intra prediction methods and apparatus. Background A large amount of video data needs to be described even in the case of short video, which can cause difficulties when the data is to be transmitted or otherwise transmitted in a communication network with limited bandwidth capacity. Video data is therefore typically compressed and then transmitted in modern telecommunication networks. Since memory resources may be limited, the size of the video may also be a problem when storing the video in a storage device. Video compression devices typically use software and/or hardware at the source side to decode video data prior to transmission or storage, thereby reducing the amount of data required to represent digital video images. The compressed data is then received at the destination side by a video decompression device for decoding the video data. With limited network resources and increasing demand for higher video quality, there is a need for improved compression and decompression techniques that can increase the compression ratio with little impact on image quality. Disclosure of Invention Embodiments of the present invention provide an intra prediction apparatus and method for encoding and decoding an image. The embodiments of the present invention should not be construed as limiting the examples set forth herein. The method provided by the first aspect of the invention comprises the steps of obtaining an intra-frame prediction mode of a current block, obtaining the availability of reference samples of components of the current block, replacing unavailable reference samples with available reference samples, obtaining the prediction of the current block according to the intra-frame prediction mode and the replaced reference samples, and reconstructing the current block according to the prediction. In one embodiment, the component includes a Y component, a Cb component, or a Cr component. In another embodiment, the component comprises a luminance component or a chrominance component. Since the first aspect of the present invention obtains the availability of the reference samples in each component, the availability information can be provided more accurately. According to one implementation of the first aspect, all Cb samples in the reconstructed block are marked as available, or all Cr samples in the reconstructed block are marked as available. Since such an implementation of the first aspect stores the available information for each sample in each component, the available information may be provided more accurately during intra prediction. According to a second aspect of the invention, the decoder comprises processing circuitry for performing the steps of the above method. According to a third aspect of the invention, an encoder comprises processing circuitry for performing the steps of the above method. According to a fourth aspect of the invention, a computer program product comprises program code which, when executed by a processor, performs the above-mentioned method. According to a fifth aspect of the invention, a decoder for intra prediction comprises one or more processing units and a non-transitory computer readable storage medium coupled to the one or more processing units and storing program instructions for execution by the one or more processing units to perform the above-described method. According to a sixth aspect of the invention, an encoder for intra prediction comprises one or more processing units and a non-transitory computer readable storage medium coupled to the one or more processing units and storing program instructions for execution by the one or more processing units to perform the above-described method. The embodiment of the invention also provides a decoding device and an encoding device for executing the method. For clarity, any of the above embodiments may be combined with any of the other embodiments described above to create new embodiments within the scope of the present invention. These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims. Drawings For a more complete understanding of the present invention, reference