Method and system for reducing gray scale discontinuities in contrast enhancing screens affected by ambient light
First Claim
1. A method of reducing a gray scale discontinuity between pixel locations in a blackened state on a contrast enhancing screen and pixel locations in a gradual shading region of an image displayed by a projector on said contrast enhancing screen, said discontinuity caused by ambient light, said method comprising:
- measuring an intensity of said ambient light;
comparing said measured ambient light intensity to an average intensity of light projected by said projector onto said gradual shading region; and
generating apparent gray scale levels for pixels to be displayed in said pixel locations in said gradual shading region based on said comparison.
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Accused Products
Abstract
A method and system for reducing a gray scale discontinuity between pixel locations in a blackened state on a contrast enhancing screen and pixel locations in a gradual shading region of an image displayed by a projector on the contrast enhancing screen. The discontinuity is caused by ambient light. The method comprises measuring an intensity of the ambient light, comparing the measured ambient light intensity to an intensity of light projected by the projector onto the gradual shading region, and generating apparent gray scale levels for the pixels to be displayed in the pixel locations in the gradual shading region based on the comparison.
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Citations
46 Claims
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1. A method of reducing a gray scale discontinuity between pixel locations in a blackened state on a contrast enhancing screen and pixel locations in a gradual shading region of an image displayed by a projector on said contrast enhancing screen, said discontinuity caused by ambient light, said method comprising:
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measuring an intensity of said ambient light;
comparing said measured ambient light intensity to an average intensity of light projected by said projector onto said gradual shading region; and
generating apparent gray scale levels for pixels to be displayed in said pixel locations in said gradual shading region based on said comparison. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of operating a light engine configured to project light onto a group of pixel locations of a viewing surface during a time period, said method comprising:
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estimating an ambient light energy received by said group of pixel locations during said time period;
determining a threshold gray scale level of the light engine; and
dithering pixels having gray scale levels at or below said threshold gray scale level to be displayed in said group of pixel locations if said estimated ambient light energy is greater than or substantially equal to said threshold gray scale level. - View Dependent Claims (8, 9, 10, 11)
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12. A method of operating a light engine configured to generate and display an image on a viewing surface, said image formed by pixels having varying gray scale levels, said method comprising:
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generating an estimate of an ambient light intensity level; and
selecting between half-toning and dithering to generate said gray scale levels for each of said pixels in response to said estimated ambient light level. - View Dependent Claims (13, 14, 15, 16)
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17. A system for reducing a gray scale discontinuity between pixel locations in a blackened state on a contrast enhancing screen and pixel locations in a gradual shading region of an image displayed by a projector on said contrast enhancing screen, said discontinuity caused by ambient light, said system comprising:
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an ambient light sensor configured to measure an intensity of said ambient light;
an image processing unit configured to compare said measured ambient light intensity to an average intensity of light projected by said projector onto said gradual shading region; and
a spatial light modulator configured to generate apparent gray scale levels for pixels to be displayed in said pixel locations in said gradual shading region based on said comparison. - View Dependent Claims (18, 19, 20, 21, 22)
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23. A light engine for displaying an image having a gradual shading region on a contrast enhancing screen, said light engine comprising:
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a spatial light modulator configured to generate gray scale levels for pixels in said image;
projector optics configured to project light comprising said image onto said contrast enhancing screen, said projected light having an intensity; and
an ambient light sensor configured to measure an intensity of ambient light reflecting off pixel locations in said contrast enhancing screen corresponding to said gradual shading region;
wherein said spatial light modulator reduces a gray scale discontinuity caused by said ambient light between pixel locations in a blackened state on said contrast enhancing screen and said pixel locations in said gradual shading region by generating apparent gray scale levels for said pixels to be displayed in said pixel locations in said gradual shading region based on a comparison between said measured ambient light intensity and said projected light intensity. - View Dependent Claims (24, 25, 26, 27)
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28. A projector system for displaying an image on a viewing surface, said system comprising:
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a light engine configured to generate pixels having gray scale levels to be displayed in corresponding pixel locations on said viewing surface; and
an ambient light sensor configured to measure an intensity of ambient light reflecting off said pixel locations on said viewing surface;
wherein said light engine is further configured to receive said measured ambient light intensity from said ambient light sensor and select between a half-toning algorithm and a dithering algorithm to generate said gray scale levels for each of said pixels based on said measured ambient light intensity. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35)
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36. A system for reducing a gray scale discontinuity between pixel locations in a blackened state on a contrast enhancing screen and pixel locations in a gradual shading region of an image displayed by a projector on said contrast enhancing screen, said discontinuity caused by ambient light, said system comprising:
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means for measuring an intensity of said ambient light;
means for comparing said measured ambient light intensity to an average intensity of light projected by said projector onto said gradual shading region; and
means for generating apparent gray scale levels for pixels to be displayed in said pixel locations in said gradual shading region based on said comparison. - View Dependent Claims (37, 38, 39)
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40. A system for operating a light engine configured to project light onto a group of pixel locations of a viewing surface during a time period, said system comprising:
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means for estimating an ambient light energy received by said group of pixel locations during said time period;
means for determining a threshold gray scale level of said light engine; and
means for dithering pixels having gray scale levels at or below said threshold gray scale level to be displayed in said group of pixel locations if said estimated ambient light energy is greater than or substantially equal to said threshold gray scale level. - View Dependent Claims (41)
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42. A system for operating a light engine configured to generate and display an image on a viewing surface, said image formed by pixels having varying gray scale levels, said system comprising:
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means for generating an estimate of an ambient light intensity level; and
means for selecting between a half-toning means and a dithering means to generate said gray scale levels for each of said pixels in response to said estimated ambient light level. - View Dependent Claims (43, 44, 45, 46)
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Specification