Dithering method and related apparatus using aperiodic tiling rule

• US 20050275899A1
• Filed: 05/03/2005
• Published: 12/15/2005
• Est. Priority Date: 05/28/2004
• Status: Abandoned Application

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Realtek Semiconductor Corp.
• Inventors: Chen, Ding-Yun
• Application Number:
  US10/908,233
• Publication Number:
  US 20050275899A1
• Time in Patent Office: Days
• US Class Current: 358/3.130
• CPC Class Codes: H04N 1/4051 producing a dispersed dots halftone pattern, the dots having substantially the same size different sizes H04N1/4057

Abstract

The present invention discloses a dithering method and related apparatus that uses the tiling rule of Wang Tiles. The disclosed method includes the following steps: providing a plurality of dithering tiles, wherein each of the plurality of dithering tiles corresponds to a threshold array; generating at least one dithering mask with the plurality of dithering tiles according to the tiling rule of Wang Tiles; and comparing the pixel values of the image with corresponding threshold values of the dithering mask on a pixel-by-pixel basis to generate a halftone image of the image.

Claims

1. A method for dithering an image, comprising:

providing a plurality of dithering tiles;

generating at least one dithering mask with the plurality of dithering tiles according to an aperiodic tiling rule; and

dithering the image with the dithering mask, so as to obtain a halftone image.

2. The method of claim 1, wherein the aperiodic tiling rule is the tiling rule of Wang Tiles.

3. The method of claim 1, wherein the image is a gray scale image or a color image.

4. The method of claim 1, wherein the dithering tiles are generated according to a generic algorithm.

5. The method of claim 4, wherein the method utilizes at least one of the dithering masks to dither the three primary colors R, G, and B of the color image respectively.

6. The method of claim 1, wherein each of the dithering tiles corresponds to a threshold array.

7. The method of claim 6, wherein values of the threshold array are compared with the pixel values to halftone the image.

8. An apparatus for dithering an image, comprising:

a first memory for storing a plurality of dithering tiles; and

a processing unit coupled to the first memory for generating at least one dithering mask with the plurality of dithering tiles according to an aperiodic tiling rule, and for dithering the image with the dithering mask, so as to obtain a halftone image.

9. The apparatus of claim 8, further comprising:

a second memory, coupled to the processing unit, for recording a usage history of the plurality of dithering tiles.

10. The apparatus of claim 8, wherein the first memory further records a usage history of the plurality of dithering tiles.

11. The apparatus of claim 8, wherein the aperiodic tiling rule is the tiling rule of Wang Tiles.

12. The apparatus of claim 8, wherein each of the dithering tiles corresponds to a threshold array, and values of the threshold array are compared with pixel values of the image.

13. A method for generating a dithering mask, comprising:

providing a plurality of dithering tiles; and

generating at least one dithering mask with the plurality of dithering tiles according to an aperiodic tiling rule.

14. The method of claim 13, wherein the aperiodic tiling rule is the tiling rule of Wang Tiles.

15. The method of claim 13, wherein the dithering mask is for dithering an image, so as to obtain a halftone image.

16. The method of claim 15, wherein the image is a gray scale image or a color image.

17. The method of claim 15, wherein the dithering tiles are generated according to a generic algorithm.

18. The method of claim 17, wherein the method utilizes at least one of the dithering masks to dither three primary colors R, G, and B of the color image respectively.

19. The method of claim 15, wherein each of the dithering tiles corresponds to a threshold array, and the method compares values of the threshold arrays with pixel values of the image.