Intra-prediction mode using downsampling for block-wise picture coding

Patent metadata

Field	Value
Publication number	US-12160606-B2
Application number	US-202318094975-A
Country	US
Kind code	B2
Filing date	Jan 9, 2023
Priority date	Mar 29, 2018
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

An apparatus for block-wise decoding a picture from a data stream and/or encoding a picture into a data stream, the apparatus supporting at least one intra-prediction mode according to which the intra-prediction signal for a block of a predetermined size of the picture is determined by applying a first template of samples which neighbours the current block onto a neural network. The apparatus may be configured, for a current block differing from the predetermined size, to:
resample a second template of samples neighboring the current block, so as to conform with the first template so as to obtain a resampled template; apply the resampled template of samples onto the neural network so as to obtain a preliminary intra-prediction signal; and resample the preliminary intra-prediction signal so as to conform with the current block so as to obtain the intra-prediction signal for the current block.

First claim

The invention claimed is:

1. A method for decoding a picture from a data stream, the method comprising:
after a first intra-prediction signal for a block of a first size of the picture is determined based on an application of a set of parameters, corresponding to a prediction mode, to a first template of samples that neighbors the block, downsampling a second template of already reconstructed samples neighboring a current block of a second size to acquire a resampled template with dimensions of the first template of samples;
generating a preliminary intra-prediction signal by applying the set of parameters to the resampled template; and
upsampling the preliminary intra-prediction signal to acquire a second intra-prediction signal, corresponding to the second size, for predicting the current block.

2. The method of claim 1 , wherein the first size is different than the second size.

3. The method of claim 1 , wherein:
the first size corresponds to a first dimension and a second dimension,
the second size corresponds to a third dimension and a fourth dimension,
the first dimension is different than the third dimension.

4. The method of claim 1 , further comprising:
determining, for the current block, to use the set of parameters used to determine the first intra-prediction signal for generating the preliminary intra-prediction signal.

5. The method of claim 1 , further comprising:
selecting a first set of prediction modes or a second set of prediction modes for the block, wherein the first set of prediction modes are adapted for different size blocks and the second set of prediction modes include a DC mode and multiple angular modes;
selecting the prediction mode from the first set of prediction modes based on the block being the first size; and
applying the selected prediction mode to the first template of samples for determining the first intra-prediction signal.

6. The method of claim 1 , further comprising:
obtaining the set of parameters, corresponding to the prediction mode that is selected from a set of prediction modes, based in part on the first size; and
applying the set of parameters to the first template of samples for determining the first intra-prediction signal.

7. The method of claim 1 , further comprising:
transforming the preliminary intra-prediction signal from a spatial domain into a transform-domain; and
upsampling the preliminary intra-prediction signal in the transform-domain.

8. An electronic device for decoding a picture from a data stream, the electronic device comprising:
a processor configured to:
after a first intra-prediction signal for a block of a first size of the picture is determined based on an application of a set of parameters, corresponding to a prediction mode, to a first template of samples that neighbors the block, down-sample a second template of already reconstructed samples neighboring a current block of a second size to acquire a resampled template with dimensions of the first template of samples;
generate a preliminary intra-prediction signal by applying the set of parameters to the resampled template; and
up-sample the preliminary intra-prediction signal to acquire a second intra-prediction signal, corresponding to the second size, for predicting the current block.

9. The electronic device of claim 8 , wherein the first size is different than the second size.

10. The electronic device of claim 8 , wherein;
the first size corresponds to a first dimension and a second dimension,
the second size corresponds to a third dimension and a fourth dimension,
the first dimension is different than the third dimension.

11. The electronic device of claim 8 , wherein the processor is further configured to:
determine, for the current block, to use the set of parameters used to determine the first intra-prediction signal for generating the preliminary intra-prediction signal.

12. The electronic device of claim 8 , wherein the processor is further configured to:
select a first set of prediction modes or a second set of prediction modes for the block, wherein the first set of prediction modes are adapted for different size blocks and the second set of prediction modes include a DC mode and multiple angular modes;
select the prediction mode from the first set of prediction modes based on the block being the first size; and
apply the selected prediction mode to the first template of samples for determining the first intra-prediction signal.

13. The electronic device of claim 8 , wherein the processor is further configured to:
obtain the set of parameters, corresponding to the prediction mode that is selected from a set of prediction modes, based in part on the first size; and
apply the set of parameters to the first template of samples for determining the first intra-prediction signal.

14. The electronic device of claim 8 , wherein the processor is further configured to:
transform the preliminary intra-prediction signal from a spatial domain into a transform-domain; and
up-sample the preliminary intra-prediction signal in the transform-domain.

15. A non-transitory computer readable medium containing instructions that when executed cause at least one processor to:
after a first intra-prediction signal for a block of a first size of a picture is determined based on an application of a set of parameters, corresponding to a prediction mode, to a first template of samples that neighbors the block, down-sample a second template of already reconstructed samples neighboring a current block of a second size to acquire a resampled template with dimensions of the first template of samples;
generate a preliminary intra-prediction signal by applying the set of parameters to the resampled template; and
up-sample the preliminary intra-prediction signal to acquire a second intra-prediction signal, corresponding to the second size, for predicting the current block.

16. The non-transitory computer readable medium of claim 15 , wherein the first size is different than the second size.

17. The non-transitory computer readable medium of claim 15 , wherein:
the first size corresponds to a first dimension and a second dimension,
the second size corresponds to a third dimension and a fourth dimension,
the first dimension is different than the third dimension.

18. The non-transitory computer readable medium of claim 15 , further containing instructions that when executed cause the at least one processor to:
determine, for the current block, to use the set of parameters used to determine the first intra-prediction signal for generating the preliminary intra-prediction signal.

19. The non-transitory computer readable medium of claim 15 , further containing instructions that when executed cause the at least one processor to:
select a first set of prediction modes or a second set of prediction modes for the block, wherein the first set of prediction modes are adapted for different size blocks and the second set of prediction modes include a DC mode and multiple angular modes;
select the prediction mode from the first set of prediction modes based on the block being the first size; and
apply the selected prediction mode to the first template of samples for determining the first intra-prediction signal.

20. The non-transitory computer readable medium of claim 15 , further containing instructions that when executed cause the at least one processor to:
obtain the set of parameters, corresponding to the prediction mode that is selected from a set of prediction

Assignees

• Fraunhofer Ges Forschung

Inventors

• Pfaff Jonathan
• Helle Philipp
• Merkle Philipp
• Stallenberger Björn
• Siekmann Mischa
• Winken Martin
• Wieckowski Adam
• Samek Wojciech
• Kaltenstadler Stephan
• Schwarz Heiko
• Marpe Detlev
• Wiegand Thomas

Classifications

• H04N19/61

  in combination with predictive coding · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04N19/11 Primary

  among a plurality of spatial predictive coding modes · CPC title

• H04N19/105 Primary

  Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction · CPC title

• H04N19/593 Primary

  involving spatial prediction techniques · CPC title