Image display system

• US 7,742,011 B2
• Filed: 10/31/2006
• Issued: 06/22/2010
• Est. Priority Date: 10/31/2006
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Damera-Venkata, Niranjan, Chang, Nelson Liang An
• Primary Examiner(s): DHARIA, PRABODH M
• Application Number:
  US11/590,173
• Publication Number:
  US 20080143978A1
• Time in Patent Office: 1,330 Days
• Field of Search: 345/1.3, 345/9, 345/87, 345/89, 345/690, 345/42, 345/1.2, 345 30- 33, 345/204, 353/30, 353/31, 353/94, 353/69, 353/99, 353/121, 359/443, 359/245, 359/618, 359/569, 380/200, 380/203, 382/156, 382/169, 382/286, 382/236, 382/254, 348/254, 348/187, 348/744
• US Class Current: 345/1.3
• CPC Class Codes: G09G 2300/026 Video wall, i.e. juxtaposition of a plurality of screens to create a display screen of bigger dimensions
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/007 Use of pixel shift techniques, e.g. by mechanical shift of the physical pixels or by optical shift of the perceived pixels
• CPC Class Codes: H04N 9/3102 using two-dimensional electronic spatial light modulators micromechanical modulators as such G02B26/0833; liquid crystal modulators as such G02F1/13
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026
• 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 projection system for displaying an arbitrary combination of superimposed and tiled images using a plurality of projectors. A sub-frame generator generates a plurality of sub-frames corresponding to an image frame for simultaneous display by the projectors in at least partially overlapping positions on a display surface. The sub-frames are generated using optimal sub-pixel blending maps that are derived by forming a simulated image to approximate a target image subject to at least one smoothing constraint between the simulated image and the target image. The target image is formed from the image frame using at least one property (e.g., luminance or color) of each of the plurality of projectors.

Claims

1. An image display system comprising:

a sub-frame generator configured to generate first and second sub-frames corresponding to an image frame using first and second optimal sub-pixel blending maps that are derived by forming a simulated image to approximate a target image subject to at least one smoothing constraint between the simulated image and the target image; and

first and second display devices configured to simultaneously display the first and the second sub-frames onto a display surface in at least partially overlapping positions;

wherein the sub-frame generator is configured to generate the first and the second sub-frames using first and second optimal black offset corrections of the first and the second display devices, respectively.

2. The image display system of claim 1 wherein the optimal sub-pixel blending maps are derived using first and second pixel characteristics of the first and the second display devices, respectively.

3. The image display system of claim 1 wherein the optimal sub-pixel blending maps are derived using first and second pixel characteristics of the first and the second display devices, respectively, first and second geometric mappings between the first and the second display devices, respectively, and a reference coordinate system, and optimal luminance corrections for the first and the second display devices, respectively.

4. The image display system of claim 1 wherein the sub-frame generator is configured to generate the first and the second sub-frames using a target color profile of the image display system and first and second inverted color profiles of the first and the second display devices, respectively.

5. The image display system of claim 1 wherein the first and the second sub-frames form first and second tiled images on the display surface.

6. The image display system of claim 1 wherein the first and the second sub-frames form a superimposed image on the display surface.

7. A method performed by an image display system, the method comprising:

accessing an image frame; and

generating first and second sub-frames from the image frame for simultaneous display by first and second display devices, respectively, in at least partially overlapping positions on a display surface so that a simulated image formed from the first and the second sub-frames approximates, subject to at least one smoothing constraint, a target image formed from the image frame and a target color profile of the image display system that is determined from first and second measured color profiles of the first and the second display devices, respectively.

8. The method of claim 7 further comprising:

forming the first sub-frame using a first reconstruction filter that specifies at least a first pixel characteristic of the first sub-frame, and forming the second sub-frame using a second reconstruction filter that specifies at least a second pixel characteristic of the second sub-frame.

9. The method of claim 7 further comprising:

forming the simulated image using a reconstruction filter that specifies a pixel characteristic of the simulated image.

10. The method of claim 7 further comprising:

determining a first set of coefficients from a reconstruction filter and a geometric mapping between a first display device configured to display the first sub-frame and a reference coordinate system;

wherein the first set of coefficients specify a plurality of weightings corresponding to a plurality of pixel locations in the image frame for each pixel location in the first sub-frame.

11. The method of claim 7 further comprising:

determining the target color profile of the image display system by determining an intersection gamut of the first and the second measured color profiles.

12. The method of claim 7 wherein the at least one smoothing constraint specifies a relationship between a target luminance profile and a simulated luminance image.

13. The method of claim 7 further comprising:

simultaneously displaying the first and the second sub-frames with the first and the second display devices, respectively, in the at least partially overlapping positions on the display surface.

14. The method of claim 7 wherein the first and the second sub-frames form first and second tiled images on the display surface.

15. The method of claim 7 wherein the first and the second sub-frames form a superimposed image on the display surface.

16. A program product comprising:

a program executable by a processing system for causing the processing system to;

access an image frame; and

generate first and second sub-frames from the image frame for simultaneous display by first and second display devices, respectively, in at least partially overlapping positions on a display surface so that a simulated luminance image formed from the first and the second sub-frames approximates a target luminance profile formed from the image frame and the luminance of each of the first and the second display devices with at least one smoothing constraint applied to a relationship between the simulated luminance image and the target luminance profile; and

a medium for storing the program.

17. The program product of claim 16 wherein the smoothing constraint is a minimization of a difference between the gradient of the target luminance profile and gradient of the simulated luminance image.

18. The program product of claim 16 wherein the smoothing constraint is minimization of the gradient of an optimal luminance correction generated with reference to the target luminance profile.

19. The program product of claim 16 wherein the program is executable by the processing system for causing the processing system to:

form the first sub-frame using a first reconstruction filter that specifies at least a first pixel characteristic of the first sub-frame, and forming the second sub-frame using a second reconstruction filter that specifies at least a second pixel characteristic of the second sub-frame.