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CN-122003859-A - Implicit LMCS codeword

CN122003859ACN 122003859 ACN122003859 ACN 122003859ACN-122003859-A

Abstract

Methods and apparatus are provided for deriving codewords to implement mapping functions in video encoders and decoders. In one embodiment, the mapping is used for a luma mapping chroma scaling function. In another embodiment, codeword estimation is performed prior to the in-loop filter. In another embodiment, codeword estimation is performed after in-loop filtering. In another embodiment, codeword information is explicitly signaled from the encoder to the decoder.

Inventors

  • D Du Vaillant
  • E. FRANCOIS
  • CHEN YA
  • F. Garr Ping

Assignees

  • 交互数字CE专利控股有限公司

Dates

Publication Date
20260508
Application Date
20240910
Priority Date
20230929

Claims (15)

  1. 1. A method, comprising: Performing extrapolation using the codeword to determine a table for the mapping function; implementing the mapping function on video blocks, and The video blocks are encoded using the mapped video blocks.
  2. 2. An apparatus, comprising: Memory, and A processor configured to: Performing extrapolation using the codeword to determine a table for the mapping function; implementing the mapping function on video blocks, and The video blocks are encoded using the mapped video blocks.
  3. 3. A method, comprising: Performing extrapolation using the codeword to determine a table for the mapping function; implementing the mapping function on video blocks, and The video blocks are decoded using the mapped video blocks.
  4. 4. An apparatus, comprising: Memory, and A processor configured to: Performing extrapolation using the codeword to determine a table for the mapping function; implementing the mapping function on video blocks, and The video blocks are decoded using the mapped video blocks.
  5. 5. A method as claimed in claim 1 or 3 or an apparatus as claimed in claim 2 or 4, wherein the calculation using codewords is performed before an in-loop filter.
  6. 6. A method as claimed in claim 1 or 3 or an apparatus as claimed in claim 2 or 4, wherein the calculation using codewords is performed after an in-loop filter.
  7. 7. The method of any of claims 1, 3, 5 or 6 or the apparatus of any of claims 2,4, 5 or 6, wherein an inverse mapping function is applied to the video block prior to storage in a reference picture buffer.
  8. 8. The method of any of claims 1,3, 5-7 or the apparatus of any of claims 2, 4, or 5-7, wherein an inverse mapping function is applied to the video block from a reference picture buffer.
  9. 9. A method as claimed in any one of claims 1, 3, 5-8 or an apparatus as claimed in any one of claims 2, 4 or 5-8, wherein the flag in the header indicates whether the luma map chroma scaling parameter is recalculated.
  10. 10. A method as claimed in any one of claims 1,3, 5-9 or a device as claimed in any one of claims 2, 4 or 5-9, wherein the flag indicates whether an implicit luma map chroma scaling mode is used.
  11. 11. The method of any of claims 1, 3, 5-10 or the apparatus of any of claims 2, 4 or 5-10, wherein codeword information is explicitly signaled in the bitstream and indicates in which adaptive parameter set the codeword information is stored.
  12. 12. An apparatus, comprising: the apparatus of claim 2, and At least one of (i), (ii) and (iii), wherein (i) the antenna is configured to receive a signal, the signal comprising the video block, (ii) the band limiter is configured to limit the received signal to a frequency band comprising the video block, (iii) the display is configured to display an output representative of the video block.
  13. 13. A non-transitory computer readable medium containing data content generated in accordance with the method of any one of claims 1 or 3 to 11 or by the apparatus of any one of claims 2 or 3 to 11 for playback using a processor.
  14. 14. A signal comprising video data generated by a method according to any one of claims 1 or 3 to 11 or by an apparatus according to any one of claims 2 or 3 to 11 for playback using a processor.
  15. 15. A computer program product comprising instructions which, when the program is executed by a computer, cause the computer to perform the method of any one of claims 1 or 3 to 11.

Description

Implicit LMCS codeword Cross Reference to Related Applications The application claims the benefit of European patent application Ser. No. 23306643.0 filed on 9/29 of 2023, the entire contents of which are incorporated herein by reference. Technical Field At least one of the present embodiments relates generally to a method or apparatus for video encoding or decoding, compression or decompression. Background To achieve high compression efficiency, image and video coding schemes typically employ prediction (including motion vector prediction) and transforms to exploit spatial and temporal redundancy in video content. In general, intra-or inter-prediction is used to make use of intra-or inter-frame correlations, and then the differences between the original image and the predicted image (often denoted as prediction errors or prediction residuals) are transformed, quantized and entropy coded. In order to reconstruct video, compressed data is decoded through inverse processes corresponding to entropy encoding, quantization, transformation, and prediction. Disclosure of Invention At least one of the present embodiments relates generally to a method or apparatus for video encoding or decoding, and more particularly, to a method or apparatus for deriving codewords to generate mapping functions in encoding and decoding processes. According to a first aspect, a method is provided. The method includes steps for performing a dead reckoning using codewords to determine a table for a mapping function, implementing the mapping function on a video block, and encoding the video block using a mapping portion of the video block. According to a second aspect, another method is provided. The method includes steps for performing a dead reckoning using codewords to determine a table for a mapping function, implementing the mapping function on a video block, and decoding the video block using a mapping portion of the video block. According to another aspect, an apparatus is provided. The apparatus includes a processor and a memory. The processor can be configured to operate on digital video data in accordance with the aforementioned method. According to another aspect, an apparatus is provided. The apparatus includes a processor and a memory. The processor can be configured to encode video blocks or decode video data by performing any of the aforementioned methods. According to another general aspect of at least one embodiment, there is provided an apparatus comprising a device according to any of the decoding embodiments, and at least one of (i), (ii) or (iii), wherein (i) an antenna is configured to receive a signal, the signal comprising the video block, (ii) a band limiter configured to limit the received signal to a frequency band comprising the video block, (iii) a display configured to display an output representative of the video block. According to another general aspect of at least one embodiment, there is provided a non-transitory computer-readable medium containing data content generated according to any one of the described encoding embodiments or variants. According to another general aspect of at least one embodiment, there is provided a signal comprising video data generated according to any one of the described encoding embodiments or variants. According to another general aspect of at least one embodiment, the video data or bitstream is formatted to include data content generated according to any one of the described encoding embodiments or variants. According to another general aspect of at least one embodiment, there is provided a computer program product comprising instructions which, when the program is executed by a computer, cause the computer to perform any of the described decoding embodiments or variants. These and other aspects, features and advantages of the general aspects will become apparent from the following detailed description of exemplary embodiments, which is to be read in connection with the accompanying drawings. Drawings FIG. 1 illustrates a block diagram of an example of a system implementing various aspects and embodiments. Fig. 2 illustrates an example of a block-based hybrid video encoder. Fig. 3 illustrates a block diagram of an exemplary video decoder. Fig. 4 illustrates an encoder in one embodiment under this aspect with a new LMCS CW dead-reckoning block placed before the in-loop filter. Fig. 5 illustrates the position of a new LMCS CW estimated block in the decoder loop in one embodiment under this aspect. Fig. 6 illustrates a LMCS CW estimated new position of a block in an encoder in a second embodiment under this aspect. Fig. 7 illustrates a LMCS CW estimated new position of a block in a decoder in a second embodiment under this aspect. Fig. 8 illustrates one embodiment of a first method under the described aspects. Fig. 9 illustrates one embodiment of a second method under the described aspects. Fig. 10 illustrates one embodiment of an apparatus under the described aspects. Fig.