Plasma display apparatus and image processing method thereof

• US 20050231446A1
• Filed: 04/13/2005
• Published: 10/20/2005
• Est. Priority Date: 04/14/2004
• Status: Abandoned Application

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Joo Young, Kim, Name Jin, Lim, Geun Soo, Hyeon, Chang Ho, Baek, Seung Chan
• Application Number:
  US11/104,587
• Publication Number:
  US 20050231446A1
• Time in Patent Office: Days
• US Class Current: 345/63
• CPC Class Codes: G09G 2320/0266 Reduction of sub-frame artefacts
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2051 with use of a spatial dither pattern
• CPC Class Codes: G09G 3/2059 using error diffusion
• CPC Class Codes: G09G 3/2062 using error diffusion in time
• CPC Class Codes: G09G 3/2077 by a combination of two or more gradation control methods
• CPC Class Codes: G09G 3/288 using AC panels

Abstract

The present invention relates to a plasma display apparatus and image processing method thereof, by which low-gray-scale expression power can be enhanced and by which halftone noise occurring in video signal implementation can be reduced. According to an embodiment of the present invention, a plasma display apparatus includes an inverse gamma correction unit performing inverse gamma correction on data of a video signal inputted from outside and a halftone unit diffusing an error component resulting from multiplying a decimal value of a gray scale value of the inverse-gamma-corrected data by each error diffusion coefficient allocated according to the gray scale value into a neighbor cell.

Claims

1. A plasma display apparatus comprising:

an inverse gamma correction unit performing inverse gamma correction on data of a video signal inputted from outside; and

a halftone unit diffusing an error component resulting from multiplying a decimal value of a gray scale value of the inverse-gamma-corrected data by each error diffusion coefficient allocated according to the gray scale value into a neighbor cell.

2. The plasma display apparatus of claim 1, further comprising an error diffusion coefficient lookup table storing unit previously storing information of the error diffusion coefficient allocated according to the gray scale value.

3. The plasma display apparatus of claim 2, wherein the halftone unit selectively uses a plurality of error diffusion coefficient lookup tables differing from each other in information of the error diffusion coefficient for each frame.

4. The plasma display apparatus of claim 1, wherein significant figures of the error diffusion coefficient is at least six bits.

5. The plasma display apparatus of claim 1, wherein the halftone unit diffuses the error component into the neighbor cell in a random direction.

6. The plasma display apparatus of claim 1, wherein the halftone unit performs halftoning on upper bits of a decimal value of the gray scale value of the data through dithering and lower bits of the decimal value through error diffusion.

7. An image processing method of a plasma display apparatus, comprising:

an inverse gamma correction step of performing inverse gamma correction on data of a video signal inputted from outside; and

a halftone step of diffusing an error component resulting from multiplying a decimal value of a gray scale value of the inverse-gamma-corrected data by each error diffusion coefficient allocated according to the gray scale value into a neighbor cell.

10. The image processing method of claim 7 or claim 9, further comprising an error diffusion coefficient lookup table storing step of previously storing information of the error diffusion coefficient allocated according to the gray scale value.

11. The image processing method of claim 10, wherein in the halftone step, a plurality of error diffusion coefficient lookup tables differing from each other in information of the error diffusion coefficient are selectively used for each frame.

12. The image processing method of claim 7, claim 8 or claim 9, wherein significant figures of the error diffusion coefficient is at least six bits.

13. The image processing method of claim 7, claim 8 or claim 9, wherein in the halftone step, halftoning is performed on upper bits of a decimal value of the gray scale value of the data through dithering and lower bits of the decimal value through error diffusion.

8. An image processing method of a plasma display apparatus, comprising:

an inverse gamma correction step of performing inverse gamma correction on data of a video signal inputted from outside; and

a halftone step of diffusing an error component resulting from multiplying a decimal value of a gray scale value of the inverse-gamma-corrected data by an error diffusion coefficient into a neighbor cell in a random direction.

9. An image processing method of a plasma display apparatus, comprising:

an inverse gamma correction step of performing inverse gamma correction on data of a video signal inputted from outside; and

a halftone step of diffusing an error component resulting from multiplying a decimal value of a gray scale value of the inverse-gamma-corrected data by each error diffusion coefficient allocated according to the gray scale value into a neighbor cell in a random direction.