Method and apparatus for calibrating a tiled display
First Claim
1. In a system for controlling a tiled display system that receives an input video signal, the tiled display system having two or more displays, each manifesting one of a number of discrete images separately onto a viewing surface or screen to form a composite image, at least one of the discrete images overlapping an adjacent discrete image to form at least one overlapping region, the improvement comprising:
- camera means for providing a capture image of at least a portion of the composite image including at least a portion of at least one overlapping region;
determining means for determining if the capture image has one or more non-desirable characteristics; and
identifying means for identifying a transformation function that can be used to process the input video signal and provide processed input video signals to selected displays to reduce the one or more non-desirable characteristics.
1 Assignment
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Accused Products
Abstract
A display system that can be calibrated and re-calibrated with a minimal amount of manual intervention. To accomplish this, one or more cameras are provided to capture an image of the display screen. The resulting captured image is processed to identify any non-desirable characteristics, including visible artifacts such as seams, bands, rings, etc. Once the non-desirable characteristics are identified, an appropriate transformation function is determined. The transformation function is used to pre-warp the input video signal that is provided to the display such that the non-desirable characteristics are reduced or eliminated from the display. The transformation function preferably compensates for spatial non-uniformity, color non-uniformity, luminance non-uniformity, and other visible artifacts.
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Citations
46 Claims
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1. In a system for controlling a tiled display system that receives an input video signal, the tiled display system having two or more displays, each manifesting one of a number of discrete images separately onto a viewing surface or screen to form a composite image, at least one of the discrete images overlapping an adjacent discrete image to form at least one overlapping region, the improvement comprising:
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camera means for providing a capture image of at least a portion of the composite image including at least a portion of at least one overlapping region;
determining means for determining if the capture image has one or more non-desirable characteristics; and
identifying means for identifying a transformation function that can be used to process the input video signal and provide processed input video signals to selected displays to reduce the one or more non-desirable characteristics. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In a system for controlling a tiled display system that receives an input video signal, the tiled display system having two or more displays, each manifesting one of a number of discrete images separately onto a viewing surface or screen to form a composite image, the improvement comprising:
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camera means for providing a capture image of at least a portion of the composite image, the tiled display system having a viewing side with said camera means located on the opposite of the viewing side;
determining means for determining if the capture image has one or more non-desirable characteristics; and
identifying means for identifying a transformation function that can be used to process the input video signal and provide processed input video signals to selected displays to reduce the one or more non-desirable characteristics. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method for controlling a display system that has two or more displays, each display manifesting one of a number of discrete images separately onto a viewing surface or screen to form a composite image, the method comprising the steps of:
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capturing a capture image of at least a portion of the composite image, the capture image being captured from a side of the viewing surface or screen that is opposite to a viewing side;
determining if the capture image has one or more non-desirable characteristics; and
identifying a transformation function that can be used to process an input video signal and provide a processed input video signal to selected displays to reduce the one or more non-desirable characteristics. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
sequentially inputting one or more input signals that correspond to a flat field image of varying intensities;
capturing a capture image of selected flat images;
identifying a luminance dome in the capture images; and
determining a transformation function that will at least partially remove the luminance domes from the composite image.
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22. A method according to claim 21, wherein the transformation function is represented by a color look up table of captured color domes, a nearest neighbor detection and identification block and an interpolation block among the nearest neighbors to determine the input level needed at the display to output the desired linear output level.
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23. A method according to claim 22, wherein the transformation function is represented, at least in part, by a number of coefficients.
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24. A method according to claim 22, wherein the transformation function is a bilinear transformation function.
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25. A method for controlling a display system that has two or more displays, each display manifesting one of a number of discrete images separately onto a viewing surface or screen to form a composite image, the method comprising the steps of:
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causing the at least one of the two or more displays to manifest a discrete image that has a predetermined pattern with a number of features;
capturing a capture image of a selected portion of the composite image;
identifying a spatial distortion in the capture image by examining the relative location of selected features in the capture image; and
determining a transformation function that will at least partially remove the spatial distortion from the composite image. - View Dependent Claims (26, 27, 28)
locating the dots in the capture image; and
identifying a transformation function that will at least partially remove the spatial distortion from the composite image by comparing the location of the dots in the capture image relative to an expected location.
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28. A method according to claim 27, wherein said locating step includes the steps of:
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calculating the dot locations by subtracting a black capture image from the capture image that includes the dots;
examining the resulting image content above a noise threshold using spatial filters which have an all-pass kernel;
measuring the center of gravity of the dots to find the corresponding dot locations;
eliminating dots whose energy threshold is below the threshold;
sorting the dot locations for correlation with known or expected dot patterns and deriving corrective transformation functions therefrom.
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29. A method for calibrating a tiled display system, the tiled display system having two or more displays, each receiving an input signal and each manifesting one of a number of discrete images separately onto a viewing surface or screen to form a composite image, the method comprising the steps of:
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providing an input signal to selected projectors to project a number of discrete images, each discrete image having a predetermined pattern with a number of corresponding features;
capturing a capture image of at least a portion of the screen using a camera device;
determining a distortion in the composite image by isolating the location of selected features in the capture image;
identifying a transformation function that can be applied to the input signal of selected displays to at least partially remove the distortion from the composite image. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
identifying a selected feature in a selected overlapping region, wherein the selected feature is manifested by a selected display;
identifying a selected feature in the selected overlapping region, wherein the selected feature is correlated to a corresponding feature;
determining the spatial relationship among the selected features; and
identifying one or more transformation functions for the display, said transformation functions effectively moving the location of the selected features on the viewing surface or screen toward a corrective location when applied to the input signal of the selected display.
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34. A method according to claim 33, wherein said first transformation function effectively moves the location of the selected features toward the corrective location by an amount that is weighted by a blending function of the tile exhibiting the selected feature.
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35. A method according to claim 33, wherein the predetermined pattern has a predetermined linear relationship among selected features.
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36. A method according to claim 35, wherein said first transformation function effectively moves the location of the selected feature toward the corresponding feature, and said second transformation function effectively moves the location of the corresponding feature toward the selected feature, while maintaining the predetermined linear relationship between the features.
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37. A method for calibrating a tiled projection display, the tiled projection display having two or more projectors, each receiving an input signal and each projecting one of a number of discrete images separately onto a screen to form a composite image, the method comprising the steps of:
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sequentially inputting to selected projectors an input signal that correspond to a flat field image of a first color for each of a number of luminance intensities;
capturing a capture image of selected flat field images, the capture image being captured from a side of the screen that is opposite to a viewing side;
determining a distortion in the projection display by examining the captured flat field images; and
identifying a transformation function that can be applied to the input signal that will at least partially remove the distortion from the composite image. - View Dependent Claims (38, 39, 40, 41)
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42. A method for calibrating a tiled projection display, the tiled projection display having two or more projectors, each receiving an input signal and each projecting one of a number of discrete images separately onto a screen to form a composite image, the method comprising the steps of:
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providing a physical template that includes a predetermined pattern adjacent the screen;
capturing a capture image of at least a portion of the physical template using a camera device; and
determining a camera distortion that is introduced by the camera device by comparing the capture image with a predetermined expectation. - View Dependent Claims (43, 44)
removing the physical template;
providing an input signal to selected projectors to project a number of discrete images, each exhibiting a predetermined pattern;
capturing a capture image of at least a portion of the screen using a camera device; and
determining a projection system distortion that is introduced by the projection system by comparing the capture image with a predetermined expectation.
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44. A method according to claim 43, further comprising the step of removing the camera distortion before determining the projection system distortion.
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45. A method for controlling a display system that has two or more displays, each display manifesting one of a number of discrete images separately onto a viewing surface or screen to form a composite image, at least one of the discrete images overlapping an adjacent discrete image to form at least one overlapping region, the method comprising the steps of:
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capturing a capture image of at least a portion of the composite image including at least a portion of one or more overlapping region;
determining if the capture image has one or more non-desirable characteristics; and
identifying a transformation function that can be used to process an input video signal and provide a processed input video signal to selected displays to reduce the one or more non-desirable characteristics.
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46. A method for calibrating a tiled projection display, the tiled projection display having two or more projectors, each receiving an input signal and each projecting one of a number of discrete images separately onto a screen to form a composite image, at least one of the discrete images overlapping an adjacent discrete image to form at least one overlapping region, the method comprising the steps of:
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sequentially inputting to selected projectors an input signal that correspond to a flat field image of a first color for each of a number of luminance intensities;
capturing a capture image of selected flat field images including at least a portion of one or more overlapping region;
determining a distortion in the projection display by examining the captured flat field images; and
identifying a transformation function that can be applied to the input signal that will at least partially remove the distortion from the composite image.
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Specification