Displaying least significant color image bit-planes in less than all image sub-frame locations

• US 20050243100A1
• Filed: 04/30/2004
• Published: 11/03/2005
• Est. Priority Date: 04/30/2004
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Childers, Winthrop D.
• Granted Patent: US 7,023,449 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T
• CPC Class Codes: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory
• CPC Class Codes: G09G 5/399 using two or more bit-mapped memories, the operations of which are switched in time, e.g. ping-pong buffers
• CPC Class Codes: H04N 2005/7466 Control circuits therefor
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time
• CPC Class Codes: H04N 9/3188 Scale or resolution adjustment scaling in general G06T3/40; resolution modifying circuits for displays in general G09G5/391

Abstract

A color image is produced from image data. Color image bit-planes are generated from the image data. Each color image bit-plane represents a time increment for displaying one color of a plurality of colors for each pixel of the color image. For each of the colors, color patterns are displayed in a plurality of image sub-frame locations. The color patterns represent the color image bit-planes. At least the least significant color image bit-planes are displayed in less than all of the image sub-frame locations.

Claims

1. A method for producing a color image from image data, the color image having pixels, the method comprising:

generating, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, a smallest time increment for each color represented by a least significant color image bit-plane;

displaying in at least one of a plurality of image sub-frame locations, for each of the plurality of colors, color patterns representing the color image bit-planes; and

displaying, for at least one of the colors, at least the least significant color image bit-planes in less than all of the image sub-frame locations.

2. The method of claim 1 wherein the image data includes color values for image frame locations and wherein generating color image bit-planes comprises:

generating image sub-frame color values from the color values for the image frame locations;

calculating color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and

compensating, with the excluded bit-planes, for differences in color represented by the color values for the image frame locations and the color image bit planes.

3. The method of claim 2 wherein compensating for differences in color comprises:

recreating, from the calculated color image bit-planes, image frame color values for the image frame locations;

computing a color error map by comparing the recreated color values to the color values from the image data;

computing correction factors to offset the error map; and

distributing the correction factors to image sub-frame locations.

4. The method of claim 1 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises displaying at least the least significant color image bit-planes in a single image sub-frame location.

5. The method of claim 1 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises displaying, for each color, all the bit-planes in a single image sub-frame location.

6. The method of claim 1 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises defining less than the full color depth of at least one of the colors in at least one of the plurality of image sub-frame locations.

7. A display system for producing a color image from image data, the color image having pixels, the display system comprising:

a sub-frame generation module configured to generate, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, the smallest time increment for each color represented by a least significant color image bit-plane, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane unequally distributed between the image sub-frames;

a spatial light modulator configured to modulate light beams to generate each of the image sub-frames;

a color light source configured to generate light beams in each of the plurality of colors, the color light source disposed to pass the light beams across the spatial light modulator; and

a periodic wobbling device configured to provide a relative displacement to the image sub-frames for displaying, in a plurality of image sub-frame locations, the image sub-frames.

8. The display system of claim 7 wherein the image data includes color values for image frame locations and wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to:

generate image sub-frame color values from the color values for the image frame locations;

calculate color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and

compensate, with the excluded bit-planes, for differences in color represented by the color values for the image frame locations and the color image bit planes.

9. The display system of claim 8 wherein the sub-frame generation module configured to compensate for differences in color comprises the sub-frame generation module configured to:

recreate, from the calculated color image bit-planes, image frame color values for the image frame locations;

compute a color error map by comparing the recreated color values to the color values from the image data;

compute correction factors to offset the error map; and

distribute the correction factors to image sub-frame locations.

10. The display system of claim 7 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane distributed into a single image sub-frame.

11. The display system of claim 7 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, for each color, all the bit-planes distributed into a single sub-frame.

12. The display system of claim 7 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, less than the full color depth of at least one of the colors defined in at least one of the image sub-frames.

13. A display system for producing a color image from image data, the color image having pixels, the display system comprising:

means for generating, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, the smallest time increment for each color represented by a least significant color image bit-plane, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane unequally distributed between the image sub-frames;

means for modulating light beams to generate each of the image sub-frames;

means for generating light beams in each of the plurality of colors, the color light source disposed to pass the light beams across the spatial light modulator; and

means for providing a relative displacement to the image sub-frames for displaying, in a plurality of image sub-frame locations, the image sub-frames.

14. The display system of claim 13 wherein the image data includes color values for image frame locations and wherein the means for generating color image bit-planes comprises:

means for generating image sub-frame color values from the color values for the image frame locations;

means for calculating color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and

means for compensating, with the excluded bit-planes, for differences in color represented by the color values for the image frame locations and the color image bit planes.

15. The display system of claim 14 wherein the means for compensating comprises:

means for compensating recreating, from the calculated color image bit-planes, image frame color values for the image frame locations;

means for computing a color error map by comparing the recreated color values to the color values from the image data;

means for computing correction factors to offset the error map; and

means for distributing the correction factors to image sub-frame locations.

16. The display system of claim 13 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane distributed into a single image sub-frame.

17. The display system of claim 13 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, for each color, all the bit-planes distributed into a single sub-frame.

18. The display system of claim 13 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, less than the full color depth of at least one of the colors defined in at least one of the image sub-frames.

19. A method for producing a color image from image data, the color image having pixels, the method comprising:

generating, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, a smallest time increment for each color represented by a least significant color image bit-plane;

displaying in at least one of a plurality of image sub-frame periods, for each of the plurality of colors, color patterns representing the color image bit-planes; and

displaying, for at least one of the colors, at least the least significant color image bit-planes in less than all of the image sub-frame periods.

20. The method of claim 19 wherein the image data includes color values for image frame periods and wherein generating color image bit-planes comprises:

generating image sub-frame color values from the color values for the image frame periods;

calculating color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and

compensating, with the excluded bit-planes, for differences in color represented by the color values for the image frame periods and the color image bit planes.

21. The method of claim 20 wherein compensating for differences in color comprises:

recreating, from the calculated color image bit-planes, image frame color values for the image frame periods;

computing a color error map by comparing the recreated color values to the color values from the image data;

computing correction factors to offset the error map; and

distributing the correction factors to image sub-frame periods.

22. The method of claim 19 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame periods comprises displaying at least the least significant color image bit-planes in a single image sub-frame period.

23. The method of claim 19 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame periods comprises displaying, for each color, all the bit-planes in a single image sub-frame period.

24. The method of claim 19 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame periods comprises defining less than the full color depth of at least one of the colors in at least one of the plurality of image sub-frame periods.

25. A display system for producing a color image from image data, the color image having pixels, the display system comprising:

a sub-frame generation module configured to generate, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, the smallest time increment for each color represented by a least significant color image bit-plane, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane unequally distributed between the image sub-frames;

a spatial light modulator configured to modulate light beams to generate each of the image sub-frames;

a color light source configured to generate light beams in each of the plurality of colors, the color light source disposed to pass the light beams across the spatial light modulator; and

a periodic wobbling device configured to provide a relative displacement to the image sub-frames for displaying, in a plurality of image sub-frame periods, the image sub-frames.

26. The display system of claim 25 wherein the image data includes color values for image frame periods and wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to:

generate image sub-frame color values from the color values for the image frame periods;

calculate color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and

compensate, with the excluded bit-planes, for differences in color represented by the color values for the image frame periods and the color image bit planes.

27. The display system of claim 26 wherein the sub-frame generation module configured to compensate for differences in color comprises the sub-frame generation module configured to:

recreate, from the calculated color image bit-planes, image frame color values for the image frame periods;

compute a color error map by comparing the recreated color values to the color values from the image data;

compute correction factors to offset the error map; and

distribute the correction factors to image sub-frame periods.

28. The display system of claim 25 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane distributed into a single image sub-frame.

29. The display system of claim 25 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, for each color, all the bit-planes distributed into a single sub-frame.

30. The display system of claim 25 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, less than the full color depth of at least one of the colors defined in at least one of the image sub-frames.

31. A display system for producing a color image from image data, the color image having pixels, the display system comprising:

means for generating, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, the smallest time increment for each color represented by a least significant color image bit-plane, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane unequally distributed between the image sub-frames;

means for modulating light beams to generate each of the image sub-frames;

means for generating light beams in each of the plurality of colors, the color light source disposed to pass the light beams across the spatial light modulator; and

means for providing a relative displacement to the image sub-frames for displaying, in a plurality of image sub-frame periods, the image sub-frames.

32. The display system of claim 31 wherein the image data includes color values for image frame periods and wherein the means for generating color image bit-planes comprises:

means for generating image sub-frame color values from the color values for the image frame periods;

means for calculating color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and

means for compensating, with the excluded bit-planes, for differences in color represented by the color values for the image frame periods and the color image bit planes.

33. The display system of claim 32 wherein the means for compensating comprises:

means for compensating recreating, from the calculated color image bit-planes, image frame color values for the image frame periods;

means for computing a color error map by comparing the recreated color values to the color values from the image data;

means for computing correction factors to offset the error map; and

means for distributing the correction factors to image sub-frame periods.

34. The display system of claim 31 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane distributed into a single image sub-frame.

35. The display system of claim 31 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, for each color, all the bit-planes distributed into a single sub-frame.

36. The display system of claim 31 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, less than the full color depth of at least one of the colors defined in at least one of the image sub-frames.