Multi-level stochastic dithering with noise mitigation via sequential template averaging

• US 8,451,298 B2
• Filed: 05/15/2008
• Issued: 05/28/2013
• Est. Priority Date: 02/13/2008
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Silverstein, Louis D., Lewis, Alan, Gille, Jennifer L.
• Primary Examiner(s): SHENG, TOM V
• Application Number:
  US12/121,706
• Publication Number:
  US 20090201318A1
• Time in Patent Office: 1,839 Days
• Field of Search: 345/84, 345/85, 345/108, 345/204, 345/616, 345/690, 345/691, 345596-600, 359/245, 359/247, 359/249, 359/276, 359/290, 359/291, 359/292
• US Class Current: 345/690
• CPC Class Codes: G09G 3/2055 the pattern being varied in time
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3466 based on interferometric effect
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

Displays, and methods of displaying images with the displays, which have quantized display characteristics for each of the pixels are disclosed. The displays and methods relate to both spatially and temporally dithering images so that the effective resolution of the display is higher than the result of the native spatial and intensity resolutions of the display, defined by pixel size, pitch, and number of quantization levels of each of the pixels.

Claims

1. A method of displaying images on a display, the method comprising:

generating a first version of a first image according to a first spatial dither template;

generating a second version of the first image according to a second spatial dither template, the second template being different from the first template;

displaying the first image by successively displaying the first and second versions of the first image on the display,

wherein the first image comprises two or more color components, and wherein the first and second versions of the first image are generated for each of the color components;

generating a first version of a second image according to a third spatial dither template;

generating a second version of the second image according to a fourth spatial dither template; and

displaying the first and second versions of the second image after displaying the first and second versions of the first image,

wherein the third and fourth templates are different from the first and second templates.

2. The method of claim 1, wherein the display has a native intensity resolution and the first image is displayed with an effective intensity resolution higher than the native intensity resolution of the display.

3. The method of claim 1, further comprising:

generating one or more additional versions of the first image according to one or more additional spatial dither templates; and

successively displaying the first, second and additional versions on the display.

4. The method of claim 3, wherein the display has a native intensity resolution and the first image is displayed with an effective intensity resolution based at least in part on the number of displayed versions of the first image.

5. The method of claim 3, wherein at least one of the additional templates is identical to one of the first and second templates.

6. The method of claim 1, wherein the first image is represented by a series of data sets, each data set representing a pixel of the first image, and generating the first and second versions of the first image comprises modifying one or more of the data sets according to the first and second templates, respectively.

7. The method of claim 6, wherein generating the first and second versions of the first image further comprises thresholding one or more of the data sets.

8. The method of claim 1, wherein the first image is substantially monochrome.

9. The method of claim 1, wherein at least one of the first and second spatial dither templates comprises a plurality of tiled stochastic templates.

10. The method of claim 1, wherein the first and second spatial dither templates are generated so as to have a mathematical relationship to one another.

11. The method of claim 10, wherein the first and second spatial dither templates are configured to reduce image noise because of the mathematical relationship.

12. The method of claim 10, wherein the first and second spatial dither templates comprise threshold values for each pixel, each of the pixels of the first template corresponding to one of the pixels of the second template, and wherein the threshold values for at least some pixels in the first template are inverses of the threshold values of the corresponding pixels in the second template.

13. The method of claim 1, wherein the temporal order of displaying the first and second versions is randomly or pseudo-randomly determined.

14. A method of displaying images on a display having a native intensity resolution, the method comprising:

generating a first version of the first image according to a first template;

generating a second version of the first image according to a second template, the second template being different from the first template;

displaying the first and second versions of the first image such that an effective resolution of the first image is higher than the native intensity resolution of the display,

wherein the first image comprises two or more color components, and wherein the first and second versions of the first image are generated for each of the color components;

generating a first version of a second image according to a third spatial dither template;

generating a second version of the second image according to a fourth spatial dither template; and

displaying the first and second versions of the second image after displaying the first and second versions of the first image,

wherein the third and fourth templates are different from the first and second templates.

15. The method of claim 14, further comprising:

generating one or more additional versions of the first image according to one or more additional templates; and

displaying the additional versions to provide further improvement in the effective resolution.

16. The method of claim 15, wherein at least one of the additional templates is substantially the same as one of the first and second templates.

17. The method of claim 14, wherein the first image is represented by a series of data sets, each data set representing a pixel of the first image, and wherein generating the first and second versions of the first image comprises modifying one or more of the data sets according to the first and second templates, respectively.

18. The method of claim 14, wherein generating the first and second versions of the first image further comprises thresholding one or more of the data sets.

19. The method of claim 14, wherein the first and second versions are displayed successively.

20. The method of claim 14, wherein the first image is substantially monochrome.

21. The method of claim 14, wherein at least one of the first and second templates comprises a plurality of tiled stochastic templates.

22. The method of claim 14, further comprising randomly or pseudo-randomly determining a temporal order for displaying the first and second versions, wherein the first and second versions are display according to the determined temporal order.

23. A method of pattern noise mitigation, the method comprising temporally averaging spatially dithered images generated with different spatial dither templates, wherein the dithered images each comprise two or more color components, and each color component is spatially dithered, and wherein a first image is generated with dithered versions of the first image, using at least first and second spatial dither templates, and a second image is generated with dithered versions of the second image, using at least third and fourth spatial dither templates, wherein the third and fourth templates are different from the first and second templates;

and wherein temporally averaging the images comprises successively generating and displaying first and second versions of an image on a display.

24. The method of claim 23, wherein the first image is represented by a series of data sets, each data set representing a pixel of the first image, and generating the first and second versions of the first image comprises modifying one or more of the data sets according to the first and second templates, respectively.

25. The method of claim 24, wherein generating the first and second versions of the first image further comprises thresholding one or more of the data sets.

26. The method of claim 23, wherein the display has a native intensity resolution and an image is displayed with an effective resolution higher than the native intensity resolution of the display.

27. The method of claim 23, wherein at least one of the spatial dither templates comprises a plurality of tiled stochastic templates.

28. The method of claim 23, wherein the spatially dithered images are displayed in a randomly or pseudo-randomly determined order.

29. A display array driver and controller circuit configured to temporally average spatially dithered images generated with different spatial dither templates, wherein the dithered images each comprise two or more color components, and each color component is spatially dithered, and wherein the driver and controller is configured to generate a first image with dithered versions of the first image, using at least first and second spatial dither templates, and to generated a second image with dithered versions of the second image, using at least third and fourth spatial dither templates, wherein the third and fourth templates are different from the first and second templates;

and wherein said driver and controller circuit is configured to sequentially output different versions of the same image generated with different spatial dither templates.

30. The display driver and controller circuit of claim 29, wherein said display driver and controller circuit is configured to

generate a first version of the first image according to the first spatial dither template;

and

generate a second version of the first image according to the second spatial dither template, the second template being different from the first template.

31. The display driver and controller circuit of claim 30, wherein said display driver and controller circuit is configured to generate one or more additional versions of the first image according to one or more additional spatial dither templates.

32. The display array driver and controller circuit of claim 29, further configured to display the spatially dithered images in a randomly or pseudo-randomly determined order.