# US 12,120,473 B2 · Video signal processing method and apparatus

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- Number: US 12,120,473 B2
- Document ID: US12120473B2
- Status: Granted
- Kind: B2
- Application number: 17/659,253
- Filed: 2022-04-14
- Published: 2022-07-28
- Granted: 2024-10-15
- Earliest claimed: 2019-10-18
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Huawei Technologies Co., Ltd.
- Inventors: Weiwei Xu; Quanhe Yu; Hu Chen; Xiaodong Xu
- Web page: https://patentgrep.com/patent/US12120473B2

## CPC

- H04N 9/68: for controlling the amplitude of colour signals, e.g. automatic chroma control circuits (H04N9/71, H04N9/73 take precedence; camera processing pipelines for controlling the colour saturation of colour signals H04N23/86)
- H04N 9/77: Circuits for processing the brightness signal and the chrominance signal relative to each other, e.g. adjusting the phase of the brightness signal relative to the colour signal, correcting differential gain or differential phase (circuits for matrixing H04N9/67)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A chrominance adjustment method and apparatus, and a storage medium are provided. The method includes: determining a color adjustment coefficient of a chrominance component of a color signal based on a reference display device maximum luminance value (RML) and/or a source maximum luminance value (SML); and adjusting the chrominance component of the color signal based on the color adjustment coefficient.

## Claims

### Claim 1

A chrominance adjustment method, comprising:
determining a color adjustment coefficient of a chrominance component of a color signal based on at least one of a reference display device maximum luminance value (RML) or a source maximum luminance value (SML), wherein the color adjustment coefficient is determined based on the following formula:
S
=
{
B
-
C
⁢
⁢
2
×
SatR
⁢
⁢
1
×
f
⁡
(
(
Y
i
⁢
n
-
A
×
R
⁢
M
⁢
L
)
(
R
⁢
M
⁢
L
-
A
×
R
⁢
M
⁢
L
)
)
,
⁢
R
⁢
⁢
M
⁢
⁢
L
>
Y
i
⁢
n
>
A
×
R
⁢
⁢
M
⁢
⁢
L
B
-
C
⁢
⁢
2
×
SatR
⁢
⁢
1
,
⁢
Y
i
⁢
n
≥
R
⁢
⁢
M
⁢
⁢
L
,
wherein
S is the color adjustment coefficient, A is an adjustment range coefficient, B is a strength range coefficient, C2 is a second correction strength factor, Yin is a luminance component value of the color signal, f(x) is a monotonically increasing function when x is in an interval 0 to 1, and SatR1 is a first saturation adjustment coefficient; and
adjusting the chrominance component of the color signal based on the color adjustment coefficient.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the at least one of the RML or the SML is determined based on a preset value, or determined based on the decoded metadata.

### Claim 3 (depends on 1)

The method according to claim 1, wherein A is a preset value, and 0<A≤1.

### Claim 4 (depends on 1)

The method according to claim 1, wherein B is a preset value, and 0<B≤1.

### Claim 5 (depends on 1)

The method according to claim 1, wherein B is determined based on the SML and a target display device maximum luminance value (TML).

### Claim 6 (depends on 5)

The method according to claim 5, wherein B is a ratio of the SML to the TML.

### Claim 7 (depends on 1)

The method according to claim 1, wherein SatR1 and SatR2 are preset values, 0<SatR1≤1, and 0<SatR2≤1.

### Claim 8 (depends on 7)

The method according to claim 7, wherein SatR1+SatR2≤1.

### Claim 9 (depends on 1)

The method according to claim 1, wherein f(x)=x.

### Claim 10 (depends on 1)

The method according to claim 1, wherein f(x)=xN, and N>0.

### Claim 11 (depends on 1)

The method according to claim 1, wherein the chrominance component is adjusted based on the following formulas:
C
b
′
=
C
b
·
S
;
⁢
and
C
r
′
=
C
r
·
S
,
wherein
Cb, Cr are chrominance components before the color signal is adjusted, and C′b,C′r are chrominance components after the color signal is adjusted.

### Claim 12

A chrominance adjustment method, comprising:
determining a color adjustment coefficient of a chrominance component of a color signal based on at least one of a reference display device maximum luminance value (RML) or a source maximum luminance value (SML), wherein the color adjustment coefficient is determined based on the following formula:
S
=
{
B
-
C
⁢
⁢
2
×
SatR
⁢
⁢
1
×
(
Y
i
⁢
n
-
A
×
R
⁢
M
⁢
L
)
(
R
⁢
M
⁢
L
-
A
×
R
⁢
M
⁢
L
)
⁢
,
⁢
R
⁢
⁢
M
⁢
⁢
L
>
Y
i
⁢
n
>
A
×
R
⁢
⁢
M
⁢
⁢
L
B
-
C
⁢
⁢
2
×
SatR
⁢
⁢
1
,
⁢
Y
i
⁢
n
≥
R
⁢
⁢
M
⁢
⁢
L
,
wherein
S is the color adjustment coefficient, A is an adjustment range coefficient, B is a strength range coefficient, C2 is a second correction strength factor, Yin is a luminance component value of the color signal, and SatR1 is a first saturation adjustment coefficient; and
adjusting the chrominance component of the color signal based on the color adjustment coefficient.

### Claim 13

A chrominance adjustment method, comprising:
determining a color adjustment coefficient of a chrominance component of a color signal based on at least one of a reference display device maximum luminance value (RML) or a source maximum luminance value (SML), wherein the color adjustment coefficient is determined based on the following formula:
S
=
{
B
-
C
⁢
⁢
2
×
SatR
⁢
⁢
1
×
f
⁢
(
(
Y
i
⁢
n
-
A
×
R
⁢
M
⁢
L
)
(
R
⁢
M
⁢
L
-
A
×
R
⁢
M
⁢
L
)
)
,
R
⁢
⁢
M
⁢
⁢
L
>
Y
i
⁢
n
>
A
×
R
⁢
⁢
M
⁢
⁢
L
B
-
C
⁢
⁢
2
×
SatR
⁢
⁢
1
-
C
⁢
⁢
2
×
SatR
⁢
⁢
2
×
g
⁡
(
(
Y
i
⁢
n
-
R
⁢
M
⁢
L
)
(
S
⁢
M
⁢
L
-
R
⁢
M
⁢
L
)
)
,
⁢
Y
i
⁢
n
≥
R
⁢
⁢
M
⁢
⁢
L
,
wherein
S is the color adjustment coefficient, A is an adjustment range coefficient, B is a strength range coefficient, C2 is a second correction strength factor, Yin is a luminance component value of the color signal, f(x) is a monotonically increasing function when x is in an interval 0 to 1, and SatR1 is a first saturation adjustment coefficient, g(x) is a monotonically increasing function when x is in an interval 0 to 1, and SatR2 is a second saturation adjustment coefficient; and
adjusting the chrominance component of the color signal based on the color adjustment coefficient.

### Claim 14 (depends on 13)

The method according to claim 13, wherein at least one of RML, SML, A, B, C2, SatR1, and SatR2 is determined based on decoded metadata, or is calculated based on information carried in the metadata.

### Claim 15 (depends on 13)

The method according to claim 13, wherein g(x)=xM, and M>0.

### Claim 16 (depends on 13)

The method according to claim 13, wherein g(x)=x.

### Claim 17

An apparatus for a chrominance adjustment, comprising:
a processor; and
a memory coupled to the processor to store instructions, which when executed by the processor, cause the apparatus to
determine a color adjustment coefficient of a chrominance component of a color signal based on at least one of a reference display device maximum luminance value (RML) or a source maximum luminance value (SML), wherein the color adjustment coefficient is determined based on the following formula:
S
=
{
B
-
C
⁢
⁢
2
×
SatR
⁢
⁢
1
×
f
⁡
(
(
Y
i
⁢
n
-
A
×
R
⁢
M
⁢
L
)
(
R
⁢
M
⁢
L
-
A
×
R
⁢
M
⁢
L
)
)
,
⁢
R
⁢
⁢
M
⁢
⁢
L
>
Y
i
⁢
n
>
A
×
R
⁢
⁢
M
⁢
⁢
L
B
-
C
⁢
⁢
2
×
SatR
⁢
⁢
1
,
⁢
Y
i
⁢
n
≥
R
⁢
⁢
M
⁢
⁢
L
,
wherein
S is the color adjustment coefficient, A is an adjustment range coefficient, B is a strength range coefficient, C2 is a second correction strength factor, Yin is a luminance component value of the color signal, f(x) is a monotonically increasing function when x is in an interval 0 to 1, and SatR1 is a first saturation adjustment coefficient; and
adjust the chrominance component of the color signal based on the color adjustment coefficient.