US 12,593,028 B2Granted

Encoder which generates prediction image to be used to encode current block

AssigneePanasonic Intellectual Property Corporation of America

InventorsTadamasa Toma, Takahiro Nishi, Kiyofumi Abe, Yusuke Kato

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Abstract

An encoder includes circuitry and memory connected to the circuitry. The circuitry, in operation: derives, as a first parameter, a total sum of absolute values of sums of horizontal gradient values respectively for pairs of relative pixel positions; derives, as a second parameter, a total sum of absolute values of sums of vertical gradient values respectively for the pairs of relative pixel positions; derives, as a third parameter, a total sum of horizontal-related pixel difference values respectively for the pairs of relative pixel positions; derives, as a fourth parameter, a total sum of vertical-related pixel difference values respectively for the pairs of relative pixel positions; derives, as a fifth parameter, a total sum of vertical-related sums of horizontal gradient values respectively for the pairs of relative pixel positions; and generates a prediction image to be used to encode the current block using the first, second, third, fourth, and fifth parameters.

Claims3

Dependent claims

An encoder comprising:

a memory;
and
a processor connected to the memory and configured to generate a prediction image in order to encode a current block based on a first parameter, a second parameter, a third parameter, a fourth parameter, and a fifth parameter that are derived in a bi-directional optical flow (BDOF) process, wherein
the first parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
abs
⁡
(
I
x
1
+
I
x
0
)
;
[
Math
.
1
]
the second parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
abs
⁡
(
I
y
1
+
I
y
0
)
;
[
Math
.
2
]
the third parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
(
-
sign
⁡
(
I
x
1
+
I
x
0
)
×
(
I
0
-
I
1
)
)
;
[
Math
.
3
]
the fourth parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
(
-
sign
⁡
(
I
y
1
+
I
y
0
)
×
(
I
0
-
I
1
)
)
;
[
Math
.
4
]
and
the fifth parameter is derived based on the following expression,
∑
[
i
,
j
]
∈
Ω
⁢
(
sign
⁡
(
I
y
1
+
I
y
0
)
×
(
I
x
1
+
I
x
0
)
)
,
[
Math
.
5
]
where:
Ω indicates a set of relative pixel positions;
[i, j] indicates a relative pixel position in the set (2 defined by a horizontal position i and a vertical position j;
Ix0 indicates a horizontal gradient value at a first pixel position in a first gradient image, and Ix1 indicates a horizontal gradient value at the first pixel position in a second gradient image, the first pixel position being determined based on a relative pixel position [i, j], the first gradient image and the second gradient image corresponding to the current block;
Iy0 indicates a vertical gradient value at the first pixel position in the first gradient image, and Iy1 indicates a vertical gradient value at the first pixel position in the second gradient image;
I0 indicates a pixel value at the first pixel position in a first interpolated image corresponding to the current block;
I1 indicates a pixel value at the first pixel position in a second interpolated image corresponding to the current block;
the abs function outputs an absolute value of an argument;
the sign function outputs a sign of an argument which is −1, 0, or 1;
and
Ix0 indicates a difference between a value of a right sample and a value of a left sample, the right sample being adjacent to a right side of a target sample, the left sample being adjacent to a left side of the target sample, the target sample being included in a first prediction block.

181 more elements

A decoder comprising:

a memory;
and
a processor connected to the memory and configured to generate a prediction image in order to decode a current block based on a first parameter, a second parameter, a third parameter, a fourth parameter, and a fifth parameter that are derived in a bi-directional optical flow (BDOF) process, wherein
the first parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
abs
⁡
(
I
x
1
+
I
x
0
)
;
[
Math
.
1
]
the second parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
abs
⁡
(
I
y
1
+
I
y
0
)
;
[
Math
.
2
]
the third parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
(
-
sign
⁡
(
I
x
1
+
I
x
0
)
×
(
I
0
-
I
1
)
)
;
[
Math
.
3
]
the fourth parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
(
-
sign
⁡
(
I
y
1
+
I
y
0
)
×
(
I
0
-
I
1
)
)
;
[
Math
.
4
]
and
the fifth parameter is derived based on the following expression,
∑
[
i
,
j
]
∈
Ω
⁢
(
sign
⁡
(
I
y
1
+
I
y
0
)
×
(
I
x
1
+
I
x
0
)
)
,
[
Math
.
5
]
where:
Ω indicates a set of relative pixel positions;
[i, j] indicates a relative pixel position in the set (2 defined by a horizontal position i and a vertical position j;
Ix0 indicates a horizontal gradient value at a first pixel position in a first gradient image, and Ix1 indicates a horizontal gradient value at the first pixel position in a second gradient image, the first pixel position being determined based on a relative pixel position [i, j], the first gradient image and the second gradient image corresponding to the current block;
Iy0 indicates a vertical gradient value at the first pixel position in the first gradient image, and Iy1 indicates a vertical gradient value at the first pixel position in the second gradient image;
I0 indicates a pixel value at the first pixel position in a first interpolated image corresponding to the current block;
I1 indicates a pixel value at the first pixel position in a second interpolated image corresponding to the current block;
the abs function outputs an absolute value of an argument;
the sign function outputs a sign of an argument which is −1, 0, or 1;
and
Ix0 indicates a difference between a value of a right sample and a value of a left sample, the right sample being adjacent to a right side of a target sample, the left sample being adjacent to a left side of the target sample, the target sample being included in a first prediction block.

181 more elements

A non-transitory computer readable medium that stores a bitstream and computer-executable instructions, the bitstream including a prediction parameter according to which the computer-executable instructions, when executed by a processor, cause a decoder to perform a decoding method of decoding a current block provided in the bitstream, the prediction parameter indicating a prediction process among prediction process candidates, the prediction process candidates including a bi-directional optical flow (BDOF) process in which a first parameter, a second parameter, a third parameter, a fourth parameter, and a fifth parameter are used to generate a prediction image of the current block, wherein

the first parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
abs
⁡
(
I
x
1
+
I
x
0
)
;
[
Math
.
1
]
the second parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
abs
⁡
(
I
y
1
+
I
y
0
)
;
[
Math
.
2
]
the third parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
(
-
sign
⁡
(
I
x
1
+
I
x
0
)
×
(
I
0
-
I
1
)
)
;
[
Math
.
3
]
the fourth parameter is derived based on the following expression:
∑
[
i
,
j
]
∈
Ω
⁢
(
-
sign
⁡
(
I
y
1
+
I
y
0
)
×
(
I
0
-
I
1
)
)
;
[
Math
.
4
]
and
the fifth parameter is derived based on the following expression,
∑
[
i
,
j
]
∈
Ω
⁢
(
sign
⁡
(
I
y
1
+
I
y
0
)
×
(
I
x
1
+
I
x
0
)
)
,
[
Math
.
5
]
where:
Ω indicates a set of relative pixel positions;
[i, j] indicates a relative pixel position in the set Ω defined by a horizontal position i and a vertical position j;
Ix0 indicates a horizontal gradient value at a first pixel position in a first gradient image, and Ix1 indicates a horizontal gradient value at the first pixel position in a second gradient image, the first pixel position being determined based on a relative pixel position [i, j], the first gradient image and the second gradient image corresponding to the current block;
Iy0 indicates a vertical gradient value at the first pixel position in the first gradient image, and Iy1 indicates a vertical gradient value at the first pixel position in the second gradient image;
I0 indicates a pixel value at the first pixel position in a first interpolated image corresponding to the current block;
I1 indicates a pixel value at the first pixel position in a second interpolated image corresponding to the current block;
the abs function outputs an absolute value of an argument;
the sign function outputs a sign of an argument which is −1, 0, or 1;
and
Ix0 indicates a difference between a value of a right sample and a value of a left sample, the right sample being adjacent to a right side of a target sample, the left sample being adjacent to a left side of the target sample, the target sample being included in a first prediction block.

178 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/756,664Filed 27 Jun 2024 · continuation
Priority: 21 Jun 2019
Published: US 2024/0348775 A117 Oct 2024
Granted: 31 Mar 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H04N 19/105
Selection of coding mode or of prediction mode: selection of the reference unit for prediction within a chosen coding or prediction mode, e.g.…
H04N 19/176
The unit being an image region, e.g. an object: the region being a block, e.g. a macroblock
H04N 19/182
Characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the…: the…
H04N 19/50
Methods or arrangements for coding, decoding, compressing or decompressing digital video signals: using predictive coding

Family

Application62/864,728Us provisional application · filed 21 Jun 2019
PCT/JP2020/023329Parent of this continuation · filed 15 Jun 2020
Application17/173,634Parent of this continuation · filed 11 Feb 2021
Application17/368,123Parent of this continuation · filed 6 Jul 2021
US 11,095,883 B2Parent of this continuation · filed 17 Aug 2021
Application18/196,763Parent of this continuation · filed 12 May 2023
US 11,689,714 B2Parent of this continuation · filed 27 Jun 2023
US 2024/0348775 A1Pre-grant publication · published 17 Oct 2024
US 12,063,358 B2Parent of this continuation
US 2021/0168357 A1Published application
US 2021/0337185 A1Published application
US 2023/0283771 A1Published application
US 12,593,028 B2This patent

From the US filing history. Foreign family members aren’t listed.