# US 7,746,408 B2 · Method and system for improving the appearance of deinterlaced chroma formatted video

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- Number: US 7,746,408 B2
- Document ID: US7746408B2
- Status: Granted
- Kind: B2
- Application number: 11/349,658
- Filed: 2006-02-08
- Published: 2007-08-09
- Granted: 2010-06-29
- Earliest claimed: 2006-02-08
- Assignees: Broadcom Corporation
- Inventors: Richard Hayden Wyman; Darren D. Neuman; Brian F. Schoner
- Web page: https://patentgrep.com/patent/US7746408B2

## CPC

- H04N 7/012: {Conversion between an interlaced and a progressive signal (for graphics images G09G2310/0229)}
- H04N 9/64: Circuits for processing colour signals (H04N9/77 takes precedence; camera processing pipelines for processing colour signals H04N23/84)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Herein described is a system and method for improving the appearance of video by generating an improved 4:2:2 chroma. The system comprises a 4:2:2 to 4:2:0 chroma regenerator that regenerates 4:2:0 chroma given a received 4:2:2 chroma, and a 4:2:0 to 4:2:2 chroma generator that weaves and interpolates the regenerated 4:2:0 chroma to yield an adjusted 4:2:2 chroma. The system further comprises a blending system used for blending the adjusted 4:2:2 chroma with the received 4:2:2 chroma based on a control input provided by a motion indication signal. The method comprises regenerating a 4:2:0 chroma from a received 4:2:2 chroma using an algorithm. The method further comprises generating an adjusted 4:2:2 chroma using the regenerated 4:2:0 chroma using another algorithm. The method further comprises blending the adjusted 4:2:2 chroma with the received 4:2:2 chroma to generate an improved 4:2:2 chroma.

## Claims

### Claim 1

A method of generating an improved 4:2:2 chroma comprising:
receiving a 4:2:2 chroma;
inputting said 4:2:2 chroma into a 4:2:2 to 4:2:0 chroma regenerator;
selecting an algorithm to be used by said 4:2:2 to 4:2:0 chroma regenerator;
using said algorithm to regenerate 4:2:0 chroma;
weaving pixels from top and bottom fields of said 4:2:0 chroma to generate a 4:2:0 chroma frame;
interpolating values provided by said 4:2:0 chroma frame to generate an adjusted 4:2:2 chroma;
inputting said adjusted 4:2:2 chroma and said 4:2:2 chroma into a blending system used for blending two inputs;
determining a first amount of said adjusted 4:2:2 chroma and a second amount of said 4:2:2 chroma for said blending; and
adding said first and second amounts to generate an improved 4:2:2 chroma.

### Claim 2 (depends on 1)

The method of claim 1 wherein said algorithm utilizes the following equations for regenerating said 4:2:0 chroma:
A
=
5
8
⁢
α
+
3
8
⁢
β
,
⁢
B
=
1
8
⁢
α
+
7
8
⁢
β
,
⁢
C
=
7
8
⁢
ɛ
+
1
8
⁢
ϕ
,
⁢
D
=
3
8
⁢
ɛ
+
5
8
⁢
ϕ
,
wherein A, B, C, and D represent 4:2:2 chroma pixel values, and α, β, ε, and φ represent 4:2:0 chroma pixel values.

### Claim 3 (depends on 2)

The method of claim 2 wherein said equations are used if said 4:2:2 chroma was generated using a 2-tap linear interpolator.

### Claim 4 (depends on 1)

The method of claim 1 wherein said algorithm utilizes the following equations for regenerating said 4:2:0 chroma:
α
=
3
4
⁢
B
-
1
+
1
4
⁢
A
β
=
3
4
⁢
B
+
1
4
⁢
A
+
1
,
⁢
ɛ
=
1
4
⁢
D
-
1
+
3
4
⁢
C
,
⁢
ϕ
=
1
4
⁢
D
+
3
4
⁢
C
+
1
,
wherein A, A+1, B, B+1, C, C+1, and D, D+1, represent 4:2:2 chroma pixel values, and α, β, ε, and φ represent 4:2:0 chroma pixel values.

### Claim 5 (depends on 1)

The method of claim 1 wherein said determining is based on an input signal for indicating the level of motion present in said 4:2:2 chroma.

### Claim 6

A method of processing a received 4:2:2 chroma formatted video to improve the appearance of displayed video comprising:
identifying undesirable pixels of said 4:2:2 chroma that are vertically interpolated using chroma associated with vertically distant 4:2:0 pixels; and
substituting chroma values associated with said undesirable pixels of said 4:2:2 chroma using a weighted average of one or more chroma values associated with one or more desirable pixels associated with said 4:2:2 chroma.

### Claim 7 (depends on 6)

The method of claim 6 wherein a weight of one or more weights of said weighted average is inversely proportional to the vertical distance between an undesirable pixel of said undesirable pixels and a desirable pixel of said one or more desirable pixels.

### Claim 8

A method of generating an improved 4:2:2 chroma comprising:
regenerating 4:2:0 chroma from a 4:2:2 chroma;
weaving said 4:2:0 chroma to produce a 4:2:0 chroma frame;
interpolating said 4:2:0 chroma frame to generate said adjusted 4:2:2 chroma; and
adding a determined first level of said 4:2:2 chroma to a determined second level of said adjusted 4:2:2 chroma.

### Claim 9 (depends on 8)

The method of claim 8 wherein said interpolating is performed by way of using the following equations:
A
new
=
1
4
⁢
ɛ
+
3
4
⁢
α
,
⁢
C
new
=
3
4
⁢
α
+
1
4
⁢
ϕ
,
⁢
B
new
=
1
4
⁢
α
+
3
4
⁢
ϕ
,
⁢
D
new
=
3
4
⁢
ϕ
+
1
4
⁢
β
,
wherein said values Anew, Bnew, Cnew, and Dnew correspond to said adjusted 4:2:2 chroma, said values Anew, Bnew, Cnew, and Dnew vertically interpolated from said values α, β, ε, and φ.

### Claim 10 (depends on 8)

The method of claim 8 wherein said regenerating is performed using the following equations:
α
=
7
4
⁢
A
-
3
4
⁢
B
,
⁢
β
=
5
4
⁢
B
-
1
4
⁢
A
,
⁢
ɛ
=
5
4
⁢
C
-
1
4
⁢
D
,
⁢
ϕ
=
7
4
⁢
D
-
3
4
⁢
C
.
wherein A, B, C, and D represent 4:2:2 chroma pixel values, and α, β, ε, and φ represent 4:2:0 chroma pixel values.

### Claim 11 (depends on 8)

The method of claim 8 wherein said regenerating is performed using the following equations:
α
=
3
4
⁢
B
-
1
+
1
4
⁢
A
β
=
3
4
⁢
B
+
1
4
⁢
A
+
1
,
⁢
ɛ
=
1
4
⁢
D
-
1
+
3
4
⁢
C
,
⁢
ϕ
=
1
4
⁢
D
+
3
4
⁢
C
+
1
,
wherein A, A+1, B, B−1, C, C+1, and D, D−1, represent 4:2:2 chroma pixel values, and α, β, ε, and φ represent 4:2:0 chroma pixel values.

### Claim 12

A system for generating improved 4:2:2 chroma pixels comprising:
a 4:2:2 to 4:2:0 chroma regenerator for converting 4:2:2 chroma to 4:2:0 chroma; and
a 4:2:0 to 4:2:2 chroma generator that weaves pixels from top and bottom fields of 4:2:0 chroma to generate a 4:2:0 chroma frame, said 4:2:0 chroma frame subsequently used for interpolating one or more pixels to generate an adjusted 4:2:2 chroma frame, wherein said 4:2:2 to 4:2:0 chroma regenerator generates chroma values of top field 4:2:0 chroma pixels, α and β, using corresponding chroma values from top field 4:2:2 chroma pixels, A and B, by way of solving the following simultaneous equations:
A
=
5
8
⁢
α
+
3
8
⁢
β
,
⁢
B
=
1
8
⁢
α
+
7
8
⁢
β
to yield the following equations:
α
=
7
4
⁢
A
-
3
4
⁢
B
,
⁢
β
=
5
4
⁢
B
-
1
4
⁢
A
.

### Claim 13

A system for generating improved 4:2:2 chroma pixels comprising:
a 4:2:2 to 4:2:0 chroma regenerator for converting 4:2:2 chroma to 4:2:0 chroma; and
a 4:2:0 to 4:2:2 chroma generator that weaves pixels from top and bottom fields of 4:2:0 chroma to generate a 4:2:0 chroma frame, said 4:2:0 chroma frame subsequently used for interpolating one or more pixels to generate an adjusted 4:2:2 chroma frame, wherein said 4:2:2 to 4:2:0 chroma regenerator generates chroma values of bottom field 4:2:0 chroma pixels, ε and φ, using corresponding chroma values from bottom field 4:2:2 chroma pixel values, C and D, by way of solving the following simultaneous equations:
C
=
7
8
⁢
ɛ
+
1
8
⁢
ϕ
,
⁢
D
=
3
8
⁢
ɛ
+
5
8
⁢
ϕ
to yield the following equations:
ɛ
=
5
4
⁢
C
-
1
4
⁢
D
,
⁢
ϕ
=
7
4
⁢
D
-
3
4
⁢
C
.

### Claim 14

A system for generating improved 4:2:2 chroma pixels comprising:
a 4:2:2 to 4:2:0 chroma regenerator for converting 4:2:2 chroma to 4:2:0 chroma; and
a 4:2:0 to 4:2:2 chroma generator that weaves pixels from top and bottom fields of 4:2:0 chroma to generate a 4:2:0 chroma frame, said 4:2:0 chroma frame subsequently used for interpolating one or more pixels to generate an adjusted 4:2:2 chroma frame, wherein said 4:2:2 to 4:2:0 chroma regenerator generates chroma values from top field 4:2:0 chroma pixels α and β, using corresponding top field 4:2:2 chroma pixel values associated with pixels A, A+1, B, and B−1 by way of utilizing the following equations:
α
=
3
4
⁢
B
-
1
+
1
4
⁢
A
β
=
3
4
⁢
B
+
1
4
⁢
A
+
1
,
wherein said B−1 denotes a pixel with spatial relationship corresponding to B, said B−1 vertically positioned at one A/B pixel pair above B, and said A+1 denotes a pixel with spatial relationship corresponding to A, said A+1 vertically positioned at one A/B pixel pair below A.

### Claim 15

A system for generating improved 4:2:2 chroma pixels comprising:
a 4:2:2 to 4:2:0 chroma regenerator for converting 4:2:2 chroma to 4:2:0 chroma; and
a 4:2:0 to 4:2:2 chroma generator that weaves pixels from top and bottom fields of 4:2:0 chroma to generate a 4:2:0 chroma frame, said 4:2:0 chroma frame subsequently used for interpolating one or more pixels to generate an adjusted 4:2:2 chroma frame, wherein said 4:2:2 to 4:2:0 chroma regenerator generates chroma values from bottom field 4:2:0 chroma pixels ε and φ, using corresponding top field 4:2:2 chroma pixel values associated with pixels C, C+1, D, and D−1 by utilizing the following equations:
ɛ
=
1
4
⁢
D
-
1
+
3
4
⁢
C
ϕ
=
1
4
⁢
D
+
3
4
⁢
C
+
1
,
wherein said D−1 denotes a pixel with spatial relationship corresponding to D, said D−1 vertically positioned at one C/D pixel pair above D, and said C+1 denotes a pixel with the spatial relationship corresponding to C, said C+1 vertically positioned at one C/D pixel pair below C.

### Claim 16

A system for generating improved 4:2:2 chroma pixels comprising:
a 4:2:2 to 4:2:0 chroma regenerator for converting 4:2:2 chroma to 4:2:0 chroma; and
a 4:2:0 to 4:2:2 chroma generator that weaves pixels from top and bottom fields of 4:2:0 chroma to generate a 4:2:0 chroma frame, wherein said 4:2:0 to 4:2:2 chroma generator computes said adjusted 4:2:2 chroma by using the following equations:
A
new
=
1
4
⁢
ɛ
+
3
4
⁢
α
,
⁢
C
new
=
3
4
⁢
α
+
1
4
⁢
ϕ
,
⁢
B
new
=
1
4
⁢
α
+
3
4
⁢
ϕ
,
⁢
D
new
=
3
4
⁢
ϕ
+
1
4
⁢
β
,
wherein said values Anew, Bnew, Cnew, and Dnew correspond to said adjusted 4:2:2 chroma, said values Anew, Bnew, Cnew, and Dnew vertically interpolated from said values α, β, ε, and φ.

### Claim 17

A system for generating improved 4:2:2 chroma pixels comprising:
a 4:2:2 to 4:2:0 chroma regenerator for converting 4:2:2 chroma to 4:2:0 chroma;
a 4:2:0 to 4:2:2 chroma generator that weaves pixels from top and bottom fields of 4:2:0 chroma to generate a 4:2:0 chroma frame, said 4:2:0 chroma frame subsequently used for interpolating one or more pixels to generate an adjusted 4:2:2 chroma frame; and
a hardware and/or software used for blending said adjusted 4:2:2 chroma to said 4:2:2 chroma, said blending used to generate an improved 4:2:2 chroma.

### Claim 18 (depends on 17)

The system of claim 17 wherein said hardware and/or software is controlled by way of an input, said input indicating the level of motion present in said 4:2:2 chroma.

### Claim 19 (depends on 18)

The system of claim 18 wherein said input controls blending of said adjusted 4:2:2 chroma and said 4:2:2 chroma such that the amount of said adjusted 4:2:2 chroma used in said blending increases as said level of motion decreases.

### Claim 20

A system for generating an improved 4:2:2 chroma comprising:
hardware operable for, at least:
receiving a 4:2:2 chroma;
inputting said 4:2:2 chroma into a 4:2:2 to 4:2:0 chroma regenerator;
selecting an algorithm to be used by said 4:2:2 to 4:2:0 chroma regenerator;
using said algorithm to regenerate 4:2:0 chroma;
weaving pixels from top and bottom fields of said 4:2:0 chroma to generate a 4:2:0 chroma frame;
interpolating values provided by said 4:2:0 chroma frame to generate an adjusted 4:2:2 chroma;
inputting said adjusted 4:2:2 chroma and said 4:2:2 chroma into a blending system used for blending two inputs;
determining a first amount of said adjusted 4:2:2 chroma and a second amount of said 4:2:2 chroma for said blending; and
adding said first and second amounts to generate an improved 4:2:2 chroma.

### Claim 21 (depends on 20)

The system of claim 20 wherein said algorithm utilizes the following equations for regenerating said 4:2:0 chroma:
A
=
5
8
⁢
α
+
3
8
⁢
β
,
⁢
B
=
1
8
⁢
α
+
7
8
⁢
β
,
⁢
C
=
7
8
⁢
ɛ
+
1
8
⁢
ϕ
,
⁢
D
=
3
8
⁢
ɛ
+
5
8
⁢
ϕ
,
wherein A, B, C, and D represent 4:2:2 chroma pixel values, and α, β, ε, and φ represent 4:2:0 chroma pixel values.

### Claim 22 (depends on 21)

The system of claim 21 wherein said equations are used if said 4:2:2 chroma was generated using a 2-tap linear interpolator.

### Claim 23 (depends on 20)

The system of claim 20 wherein said algorithm utilizes the following equations for regenerating said 4:2:0 chroma:
α
=
3
4
⁢
B
-
1
+
1
4
⁢
A
β
=
3
4
⁢
B
+
1
4
⁢
A
+
1
,
⁢
ɛ
=
1
4
⁢
D
-
1
+
3
4
⁢
C
,
⁢
ϕ
=
1
4
⁢
D
+
3
4
⁢
C
+
1
,
wherein A, A+1, B, B−1, C, C+1, and D, D−1, represent 4:2:2 chroma pixel values, and α, β, ε, and φ represent 4:2:0 chroma pixel values.

### Claim 24 (depends on 20)

The system of claim 20 wherein said determining is based on an input signal for indicating the level of motion present in said 4:2:2 chroma.

### Claim 25

A system for processing a received 4:2:2 chroma formatted video to improve the appearance of displayed video comprising:
hardware operable for, at least:
identifying undesirable pixels of said 4:2:2 chroma that are vertically interpolated using chroma associated with vertically distant 4:2:0 pixels; and
substituting chroma values associated with said undesirable pixels of said 4:2:2 chroma using a weighted average of one or more chroma values associated with one or more desirable pixels associated with said 4:2:2 chroma.

### Claim 26 (depends on 25)

The system of claim 25 wherein a weight of one or more weights of said weighted average is inversely proportional to the vertical distance between an undesirable pixel of said undesirable pixels and a desirable pixel of said one or more desirable pixels.

### Claim 27

A system for generating an improved 4:2:2 chroma comprising:
hardware operable for, at least:
regenerating 4:2:0 chroma from a 4:2:2 chroma;
weaving said 4:2:0 chroma to produce a 4:2:0 chroma frame;
interpolating said 4:2:0 chroma frame to generate said adjusted 4:2:2 chroma; and
adding a determined first level of said 4:2:2 chroma to a determined second level of said adjusted 4:2:2 chroma.

### Claim 28 (depends on 27)

The system of claim 27 wherein said interpolating is performed by way of using the following equations:
A
new
=
1
4
⁢
ɛ
+
3
4
⁢
α
,
⁢
C
new
=
3
4
⁢
α
+
1
4
⁢
ϕ
,
⁢
B
new
=
1
4
⁢
α
+
3
4
⁢
ϕ
,
⁢
D
new
=
3
4
⁢
ϕ
+
1
4
⁢
β
,
wherein said values Anew, Bnew, Cnew, and Dnew correspond to said adjusted 4:2:2 chroma, said values Anew, Bnew, Cnew, and Dnew vertically interpolated from said values α, β, ε, and φ.

### Claim 29 (depends on 27)

The system of claim 27 wherein said regenerating is performed using the following equations:
α
=
7
4
⁢
A
-
3
4
⁢
B
,
⁢
β
=
5
4
⁢
B
-
1
4
⁢
A
,
⁢
ɛ
=
5
4
⁢
C
-
1
4
⁢
D
,
⁢
ϕ
=
7
4
⁢
D
-
3
4
⁢
C
,
wherein A, B, C, and D represent 4:2:2 chroma pixel values, and α, β, ε, and φ represent 4:2:0 chroma pixel values.

### Claim 30 (depends on 27)

The system of claim 27 wherein said regenerating is performed using the following equations:
α
=
3
4
⁢
B
-
1
+
1
4
⁢
A
β
=
3
4
⁢
B
+
1
4
⁢
A
+
1
,
⁢
ɛ
=
1
4
⁢
D
-
1
+
3
4
⁢
C
,
⁢
ϕ
=
1
4
⁢
D
+
3
4
⁢
C
+
1
,
wherein A, A+1, B, B−1, C, C+1, and D, D−1, represent 4:2:2 chroma pixel values, and α, β, ε, and φ represent 4:2:0 chroma pixel values.