System and method for calibrating a display system using manual and semi-manual techniques

• US 9,369,683 B2
• Filed: 11/15/2011
• Issued: 06/14/2016
• Est. Priority Date: 11/15/2010
• Status: Active Grant

• Current Assignee: Scalable Display Technologies, Inc.
• Original Assignee: Scalable Display Technologies, Inc.
• Inventors: Timoner, Samson J., Johnson, Tyler M., Hsu, Eugene, Surati, Rajeev J., Amaratunga, Kevin
• Primary Examiner(s): Chavez, Renee D
• Application Number:
  US13/296,864
• Publication Number:
  US 20120120372A1
• Time in Patent Office: 1,673 Days
• Field of Search: 353/69, 353/70
• US Class Current: 1/1
• CPC Class Codes: G03B 21/147 Optical correction of image distortions, e.g. keystone
• CPC Class Codes: G06T 5/80 Geometric correction
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3197 using light modulating optical valves

Abstract

The invention provides a system and method that reduces the tediousness of the manual alignment process. Users select correspondences between projectors or components of a projector, to form a common coordinate. Using models of the display system, and projectors, the common coordinate system can be mapped quickly to the entire display. The process avoids a need to measure screen points, and allows the user to move significantly fewer points. Alternatively, the invention allows introduction of machine-vision style algorithms into manual calibration techniques to improve performance. This overcomes the tediousness of prior systems by introducing models of the display into the manual alignment process, allowing selection of a small number of points on each projector, and avoiding selection of precisely measured screen points. The system conversely finds correspondences between projectors, allowing mapping of the projectors into a common coordinate system, and quick warping of the coordinate system to the screen.

Claims

1. A method for calibrating one or more projectors, comprising:

displaying, via a first projector, a first projected image on a screen;

displaying, via a second projector, a second projected image on the screen, thereby defining an overlap region whereby the first projected image and the second projected image overlap on the screen;

selecting a first plurality of correspondences corresponding to the first projector and displaying the selected first plurality of correspondences with the first projected image in the overlap region on the screen, the first plurality of correspondences comprising four or fewer correspondences;

selecting a second plurality of correspondences corresponding to the second projector and displaying the selected second plurality of correspondences with the first projected image in the overlap region on the screen such that the each of the first plurality of correspondences displayed on the screen overlap with and correspond to a respective one of the second plurality of correspondences displayed on the screen, the second plurality of correspondences comprising four or fewer correspondences;

determining a first mapping from the first projector to the second projector using the selected first plurality of four or fewer correspondences displayed on the screen and the overlapping selected second plurality of four or fewer correspondences displayed on the screen, thereby defining a common coordinate system among the first projector and the second projector;

selecting a third plurality of correspondences corresponding to points on the screen, at least one of the third plurality of correspondences corresponding to a corner of the screen and being outside of the overlap region; and

determining a second mapping from the common coordinate system to the screen using the selected third plurality of correspondences;

displaying, via both the first projector and the second projector, an image on the screen based upon the first mapping and the second mapping.

2. The method of claim 1, wherein the first plurality of correspondences and the second plurality of correspondences are at arbitrary positions within the overlap region.

3. The method of claim 1, wherein at least a portion of the screen is selected from the group consisting of:

a flat screen;

a cylindrical screen; and

an extruded screen.

4. The method of claim 3, wherein determining the second mapping is performed based at least in part on a geometry of the screen.

5. The method of claim 1, further comprising transmitting, via a communication link, setting information to at least one of the first projector and the second projector, the setting information including at least one of (a) projector values, (b) warping box values,(c) OMTE parameters, (d) color curve parameters, (e) a desired resolution of a DOPP screen.

6. The method of claim 1, where in at least one of the third plurality of correspondences includes at least one of:

a boundary point;

a curve; and

an edge.

7. The method of claim 1, wherein the displaying the image step further comprises:

updating the displayed image in real time based on updates to at least one of the first mapping and the second mapping.

8. The method of claim 1, wherein determining the first mapping and determining the second mapping are performed concurrently.

9. The method of claim 1, wherein the step of selecting the first plurality and second plurality of correspondences displays images on the screen defined by intensity fall-offs at intended selected correspondences, whereby the images of the first projector and second projector are movable to achieve sub-pixel matches between the images of the first projector and the second projector.

10. The method of claim 1, wherein the step of selecting the first plurality and second plurality of correspondences comprises displaying the correspondences in a different color within the overlap region to allow identification of alignment as at least two colors combining to form a new color.

11. The method of claim 1, wherein determining the first mapping comprises identifying an estimate of a first mapping and refining the estimate of the first mapping based on the first and second plurality of correspondences.

12. The method of claim 1, wherein the first plurality of correspondences and second plurality of correspondences are arbitrarily selected in the overlap region.

13. A system for calibrating one or more projectors, comprising:

first projector for displaying a first projected image on a screen;

a second projector for display a second projected image on the screen, thereby defining an overlap region whereby the first projected image and the second projected image overlap on the screen; and

a processor configured to;

select a first plurality of correspondences corresponding to the first projector for displaying the selected first plurality of correspondences with the first projected image in the overlap region on the screen, the first plurality of correspondences comprising four or fewer correspondences;

select a second plurality of correspondences corresponding to the second projector for displaying the selected second plurality of correspondences with the second projected image in the overlap region on the screen such that the each of the first plurality of correspondences displayed on the screen overlap with and correspond to a respective one of the second plurality of correspondences displayed on the screen, the second plurality of correspondences comprising four or fewer correspondences;

determine a first mapping from the first projector to the second projector using the selected first plurality of four or fewer correspondences displayed on the screen and the overlapping selected second plurality of four or fewer correspondences displayed on the screen, thereby defining a common coordinate system among the first projector and the second projector;

select a third plurality of correspondences corresponding to points on the screen, at least one of the third plurality of correspondences corresponding to a corner of the screen and being outside of the overlap region; and

determine a second mapping from the common coordinate system to the screen using the selected third plurality of correspondences;

wherein an image is displayed on the screen, based upon the first mapping and the second mapping.