Color image processing apparatus, color image processing method, program and recording medium

• US 7,643,094 B2
• Filed: 10/27/2004
• Issued: 01/05/2010
• Est. Priority Date: 10/30/2003
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Tanaka, Masanobu, Kawashima, Masahiro, Ogasawara, Masakazu
• Primary Examiner(s): LEE, MICHAEL
• Application Number:
  US10/577,031
• Publication Number:
  US 20090009664A1
• Time in Patent Office: 1,896 Days
• Field of Search: 348/655, 348/656, 348/649, 348/651, 348/652, 348659-662, 348/742, 348/743, 348/771, 345600-605
• US Class Current: 348/655
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

A color image processing apparatus performs color image display using a red display, green display, blue display and white display. The apparatus includes a white signal generation circuit generating a white signal W based on an input red signal R_in for the red display, an input green signal G_in for the green display, and an input blue signal B_in for the blue display, a yellow signal generation circuit generating a yellow signal Ye, based on the input red signal R_in, the input green signal G_in, and the generated white signal W, and a first output white signal generation circuit generating a first output white signal W_out⁽¹⁾ for the white display, based on the generated white signal W and the generated yellow signal Ye.

Claims

1. A color image processing apparatus of performing a color image display using a red display, a green display, a blue display and a white display, comprising:

white signal generation instrument which generates a white signal

W=min(R_in,G_in,B_in), 

 

(Formula

     1)

based on an input red signal R_in for making said red display to be inputted, an input green signal G_in for making said green display to be inputted, and an input blue signal B_in for making said blue display to be inputted;

yellow signal generation instrument which generates a yellow signal

Ye=min(R_in−

W,G_in−

W), 

 

(Formula

     2)

based on said input red signal R_in to be inputted, said input green signal G_in to be inputted, and said generated white signal W; and

first output white signal generation instrument which generates a first output white signal W_out⁽¹⁾ for making said white display to be outputted, based on said generated white signal W and said generated yellow signal Y,

wherein said first output white signal generation instrument generates said first output white signal W_out⁽¹⁾

W_out⁽¹⁾=W+K₁·

Ye 

 

(Formula

     3)

for a predetermined positive constant K₁.

2. The color image processing apparatus according to claim 1, further comprising output blue signal generation instrument which generates an output blue signal B_out for making said blue display to be outputted, based on said input blue signal B_in for making the blue display to be inputted, said generated yellow signal Ye, and said generated white signal W.

3. The color image processing apparatus according to claim 2, wherein said output blue signal generation instrument generates said output blue signal B_out

B_out=B_in−

L₁·

Ye·

W 

 

(Formula

     4)

for a predetermined positive constant L₁.

4. The color image processing apparatus according to claim 1, further comprising cyan signal generation instrument which generates a cyan signal

Cy=min(G_in−

W,B_in−

W), 

 

(Formula

     5)

based on said input green signal G_in to be inputted, said input blue signal B_in to be inputted, and said generated white signal W, and

second output white signal generation instrument which generates a second output white signal W_out⁽²⁾ for making said white display to be outputted, instead of said first output white signal W_out⁽¹⁾, based on said generated first output white signal W_out⁽¹⁾ and said generated cyan signal Cy.

5. The color image processing apparatus according to claim 4, wherein said second output white signal generation instrument generates said second output white signal W_out⁽²⁾

W_out⁽²⁾=W_out⁽¹⁾+K₂·

Cy 

 

(Formula

     6)

for a predetermined positive constant K₂.

6. The color image processing apparatus according to claim 4, further comprising output red signal generation instrument which generates an output red signal R_out for making said red display to be outputted, based on said input red signal R_in for making the red display to be inputted, said generated cyan signal Cy, and said generated first output white signal W_out⁽¹⁾.

7. The color image processing apparatus according to claim 6, wherein said output red signal generation instrument generates said output red signal R_out

R_out=R_in−

L₂·

Cy·

W_out⁽¹⁾ 

 

(Formula

     7)

for a predetermined positive constant L₂.

8. The color image processing apparatus according to claim 4, further comprising magenta signal generation instrument which generates a magenta signal

Ma=min(B_in−

W,R_in−

W), 

 

(Formula

     8)

based on said input blue signal B_in to be inputted, said input red signal R_in to be inputted, and said generated white signal W, and

third output white signal generation instrument which generates a third output white signal W_out⁽³⁾ for making said white display to be outputted, instead of said second output white signal W_out⁽²⁾, based on said generated second output white signal W_out⁽²⁾ and said generated magenta signal Ma.

9. The color image processing apparatus according to claim 8, wherein said third output white signal generation instrument generates said third output white signal W_out⁽³⁾

W_out⁽³⁾=W_out⁽²⁾+K₃·

Ma 

 

(Formula

     9)

for a predetermined positive constant K₃.

10. The color image processing apparatus according to claim 8, further comprising output green signal generation instrument which generates an output green signal G_out for making said green display to be outputted, based on said input green signal G_in for making the green display to be inputted, said generated magenta signal Ma, and said generated second output white signal W_out⁽²⁾.

11. The color image processing apparatus according to claim 10, wherein said output green signal generation instrument generates said output green signal G_out

G_out=G_in−

L₃·

Ma·

W_out⁽²⁾ 

 

(Formula

     10)

for a predetermined positive constant L₃.

12. A color image processing method of performing a color image display using a red display, a green display, a blue display and a white display, comprising:

a white signal generation step of generating a white signal

W=min(R_in,G_in,B_in), 

 

(Formula

     1)

based on an input red signal R_in for making said red display to be inputted, an input green signal G_in for making said green display to be inputted, and an input blue signal B_in for making said blue display to be inputted;

a yellow signal generation step of generating a yellow signal

Ye=min(R_in−

W,G_in−

W), 

 

(Formula

     2)

based on said input red signal R_in to be inputted, said input green signal G_in to be inputted, and said generated white signal W; and

a first output white signal generation step of generating a first output white signal W_out⁽¹⁾ for making said white display to be outputted, based on said generated white signal W and said generated yellow signal Y,

wherein said first output white signal W_out⁽¹⁾ is generated as

W_out⁽¹⁾=W+K₁·

Ye 

 

(Formula

     3)

for a predetermined positive constant K₁.

13. The color image processing method according to claim 12, further comprising an output blue signal generation step of generating an output blue signal B_out for making said blue display to be outputted, based on said input blue signal B_in for making the blue display to be inputted, said generated yellow signal Ye, and said generated white signal W.

14. The color image processing method according to claim 12, further comprising a cyan signal generation step of generating a cyan signal

Cy=min(G_in−

W,B_in−

W), 

 

(Formula

     5)

based on said input green signal G_in to be inputted, said input blue signal B_in to be inputted, and said generated white signal W, and

a second output white signal generation step of generating a second output white signal W_out⁽²⁾ for making said white display to be outputted, instead of said first output white signal W_out⁽¹⁾, based on said generated first output white signal W_out⁽¹⁾ and said generated cyan signal Cy.

15. The color image processing method according to claim 14, further comprising an output red signal generation step of generating an output red signal R_out for making said red display to be outputted, based on said input red signal R_in for making the red display to be inputted, said generated cyan signal Cy, and said generated first output white signal W_out⁽¹⁾.

16. The color image processing method according to claim 14, further comprising a magenta signal generation step of generating a magenta signal

Ma=min(B_in−

W,R_in−

W), 

 

(Formula

     8)

based on said input blue signal B_in to be inputted, said input red signal R_in to be inputted, and said generated white signal W, and

a third output white signal generation step of generating a third output white signal W_out⁽³⁾ for making said white display to be outputted, instead of said second output white signal W_out⁽²⁾, based on said generated second output white signal W_out⁽²⁾ and said generated magenta signal Ma.

17. The color image processing method according to claim 16, further comprising an output green signal generation step of generating an output green signal G_out for making said green display to be outputted, based on said input green signal G_in for making the green display to be inputted, said generated magenta signal Ma, and said generated second output white signal W_out⁽²⁾.

18. A recording medium which is computer processable and records a program for enabling a computer to perform the color image processing method according to claim 12, comprising:

a white signal generation step of generating a white signal

W=min(R_in,G_in,B_in), 

 

(Formula

     1)

based on an input red signal R_in for making said red display to be inputted, an input green signal G_in for making said green display to be inputted, and an input blue signal B_in for making said blue display to be inputted;

a yellow signal generation step of generating a yellow signal

Ye=min(R_in−

W,G_in−

W), 

 

(Formula

     2)

based on said input red signal R_in to be inputted, said input green signal G_in to be inputted, and said generated white signal W; and

a first output white signal generation step of generating a first output white signal W_out⁽¹⁾ for making said white display to be outputted, based on said generated white signal W and said generated yellow signal Ye.