Colour component prediction method, encoder, decoder and storage medium
View Patent ↗Disclosed are a colour component prediction method, an encoder, a decoder, and a storage medium. The method includes: determining adjacent reference pixels of a current block in a picture; constructing a subset of adjacent reference pixels according to the adjacent reference pixels, wherein the subset of adjacent reference pixels contains a part of the adjacent reference pixels; and calculating model parameters of a prediction model according to the subset of adjacent reference pixels, wherein the prediction model includes N prediction sub-models, the N prediction sub-models correspond to N groups of model parameters, and the prediction sub-models are used to perform, through corresponding model parameters, cross-component prediction of colour components to be predicted.
1 . A method for predicting colour components, which is applied to an encoder, the method comprising:
determining adjacent reference samples of a current block in a picture;
constructing a subset of adjacent reference samples according to the adjacent reference samples, wherein the subset of adjacent reference samples contains a part of the adjacent reference samples; and
calculating model parameters of a prediction model according to the subset of adjacent reference samples, wherein the prediction model is configured to perform cross-component prediction of colour components to be predicted,
wherein constructing the subset of adjacent reference samples according to the adjacent reference samples comprises:
determining candidate positions of candidate samples based on at least one edge of the current block; and determining reference samples corresponding to the candidate positions from the adjacent reference samples, and forming the subset of adjacent reference samples with the determined reference samples;
wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
calculating a first sampling interval according to a preset number of candidate samples and a length of the at least one edge of the current block; and determining a reference point from the at least one edge of the current block, and determining the candidate positions according to the first sampling interval.
2 . The method of claim 1 , wherein determining the adjacent reference samples of the current block in the picture comprises:
acquiring reference samples adjacent to at least one edge of the current block, wherein the at least one edge of the current block comprises at least one of: an upper row, a right upper row, a left column and a left lower column; and
obtaining the adjacent reference samples according to the acquired reference samples.
3 . The method of claim 1 , wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
determining the candidate positions based on sample positions corresponding to reference samples adjacent to the at least one edge of the current block.
4 . The method of claim 1 , wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
determining the candidate positions based on colour component intensity values corresponding to reference samples adjacent to the at least one edge of the current block.
5 . The method of claim 1 , wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
determining the candidate positions based on sample positions and colour component intensity values corresponding to the reference samples adjacent to the at least one edge of the current block.
6 . The method of claim 1 , wherein the candidate positions of the candidate samples are determined according to formulas of:
Δ
=
length
/
(
N
2
/
2
)
shift
=
Δ
/
2
wherein Δ represents a sampling interval, length represents a quantity of reference samples in a row adjacent to an upper edge of the current block or a quantity of reference samples in a column adjacent to a left edge of the current block, N 2 represents an expected quantity of reference samples forming the subset of adjacent reference samples of the current block, and shift represents a starting point position of a determined reference sample.
7 . The method of claim 1 , wherein after calculating the first sampling interval, the method further comprises:
adjusting the first sampling interval to obtain a second sampling interval; and
determining the candidate positions according to the second sampling interval based on the reference point.
8 . A method for predicting colour components, which is applied to a decoder, the method comprising:
determining adjacent reference samples of a current block in a picture;
constructing a subset of adjacent reference samples according to the adjacent reference samples, wherein the subset of adjacent reference samples contains a part of the adjacent reference samples; and
calculating model parameters of a prediction model according to the subset of adjacent reference samples, wherein the prediction model is configured to perform cross-component prediction of colour components to be predicted,
wherein constructing the subset of adjacent reference samples according to the adjacent reference samples comprises:
determining candidate positions of candidate samples based on at least one edge of the current block; and determining reference samples corresponding to the candidate positions from the adjacent reference samples, and forming the subset of adjacent reference samples with the determined reference samples;
wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
calculating a first sampling interval according to a preset number of candidate samples and a length of the at least one edge of the current block; and determining a reference point from the at least one edge of the current block, and determining the candidate positions according to the first sampling interval.
9 . The method of claim 8 , wherein determining the adjacent reference samples of the current block in the picture comprises:
acquiring reference samples adjacent to at least one edge of the current block, wherein the at least one edge of the current block comprises at least one of: an upper row, a right upper row, a left column and a left lower column; and
obtaining the adjacent reference samples according to the acquired reference samples.
10 . The method of claim 8 , wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
determining the candidate positions based on sample positions corresponding to reference samples adjacent to the at least one edge of the current block.
11 . The method of claim 8 , wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
determining the candidate positions based on colour component intensity values corresponding to reference samples adjacent to the at least one edge of the current block.
12 . The method of claim 8 , wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
determining the candidate positions based on sample positions and colour component intensity values corresponding to the reference samples adjacent to the at least one edge of the current block.
13 . The method of claim 8 , wherein the candidate positions of the candidate samples are determined according to formulas of:
Δ
=
length
/
(
N
2
/
2
)
shift
=
Δ
/
2
wherein Δ represents a sampling interval, length represents a quantity of reference samples in a row adjacent to an upper edge of the current block or a quantity of reference samples in a column adjacent to a left edge of the current block, N 2 represents an expected quantity of reference samples forming the subset of adjacent reference samples of the current block, and shift represents a starting point position of a determined reference sample.
14 . The method of claim 8 , wherein after calculating the first sampling interval, the method further comprises:
adjusting the first sampling interval to obtain a second sampling interval; and
determining the candidate positions according to the second sampling interval based on the reference point.
15 . An encoder comprising a first memory and a first processor, wherein
the first memory is configured to store a computer program runnable on the first processor; and
the first processor is configured to, when running the computer program, perform the method of claim 1 .
16 . A decoder comprising a second memory and a second processor, wherein
the second memory is configured to store a computer program runnable on the second processor; and
the second processor is configured to, when running the computer program, perform the method of claim 8 .
17 . A computer-readable storage medium, having a computer program and a bitstream stored thereon, wherein the computer program, when executed by a processor, enables the processor to perform the following operations to generate the bitstream:
determining adjacent reference samples of a current block in a picture;
constructing a subset of adjacent reference samples according to the adjacent reference samples, wherein the subset of adjacent reference samples contains a part of the adjacent reference samples; and
calculating model parameters of a prediction model according to the subset of adjacent reference samples, wherein the prediction model is configured to perform cross-component prediction of colour components to be predicted,
wherein constructing the subset of adjacent reference samples according to the adjacent reference samples comprises:
determining candidate positions of candidate samples based on at least one edge of the current block; and determining reference samples corresponding to the candidate positions from the adjacent reference samples, and forming the subset of adjacent reference samples with the determined reference samples;
wherein determining the candidate positions of the candidate samples based on the at least one edge of the current block comprises:
calculating a first sampling interval according to a preset number of candidate samples and a length of the at least one edge of the current block; and determining a reference point from the at least one edge of the current block, and determining the candidate positions according to the first sampling interval.