Correction of a projected image based on a reflected image

• US 20040140981A1
• Filed: 01/21/2003
• Published: 07/22/2004
• Est. Priority Date: 01/21/2003
• Status: Active Grant

• Current Assignee: James E. Clark
• Original Assignee: James E. Clark
• Inventors: Clark, James E.
• Granted Patent: US 7,184,054 B2
• Time in Patent Office: Days
• US Class Current: 345/600
• CPC Class Codes: H04N 9/3182 Colour adjustment, e.g. white balance, shading or gamut white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607
• 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 9/3194 including sensor feedback

Abstract

A method of color-correcting a projected image is disclosed, including providing image data for a desired image, projecting the desired image onto a surface to produce a reflected image, comparing the reflected image to the image data to determine an observed difference, and modifying the projected image to reduce the observed difference.

Claims

1. A method of presenting a projected image, comprising:

providing image data for a desired image;

projecting the desired image onto a surface to produce a reflected image;

comparing the reflected image to the image data to determine an observed difference; and

modifying the projected image to reduce the observed difference.

2. The method of claim 1, further comprising recording color data from the reflected image.

3. The method of claim 2, further comprising:

segmenting the image data into a plurality of subunits; and

segmenting the recorded color data into a corresponding plurality of subunits.

4. The method of claim 3, where comparing the reflected image to the image data includes determining an average color for each image data subunit, and determining an average color for each reflected image subunit.

5. The method of claim 4, where comparing the reflected image to the image data includes comparing image data average color to reflected image average color for at least one subunit to determine the observed difference.

6. The method of claim 1, where modifying the projected image includes determining a correction factor to reduce the observed difference.

7. The method of claim 6, where modifying the projected image includes applying the correction factor to the image data.

8. The method of claim 6, where modifying the projected image includes applying the correction factor to commands received by a light engine to create the projected image.

9. The method of claim 6, where modifying the projected image includes applying the correction factor to one or more operating parameters of a light engine used to create the projected image.

10. A method of color-correcting an image, comprising:

providing image data for a desired image;

projecting an image derived from the image data onto a surface to produce a reflected image;

calculating a desired average color for a subunit of the desired image;

determining an average color for a corresponding subunit of the reflected image;

determining a difference between the desired average color and the determined average color;

determining a correction factor configured to reduce the determined difference between the desired and determined average colors;

applying the correction factor to a projection value; and

projecting a corrected image using the corrected projection value.

11. The method of claim 10, where calculating a desired average color, determining an average color, and determining a difference between the desired average color and the determined average color is repeated for each subunit of the desired image and corresponding subunit of the reflected image.

12. The method of claim 10, where an average color includes one or more of an average red intensity, an average blue intensity, and an average green intensity.

13. The method of claim 10, where determining an average color for the reflected image includes converting the reflected image to reflected image data.

14. The method of claim 10, further comprising capturing the reflected image using a camera.

15. The method of claim 10, where the projection value includes the image data.

16. The method of claim 10, where the projection value includes one or more light engine commands derived from the image data.

17. The method of claim 10, where the projection parameter includes one or more operating parameters of a light engine.

18. The method of claim 10, further comprising:

determining an average color for the corresponding subsection of the reflected corrected image;

determining a revised difference between the desired average color and the determined corrected average color;

determining a revised correction factor configured to reduce the determined revised difference;

applying the revised correction factor to a projection value; and

projecting a revised corrected image using the revised corrected projection value.

19. A display device comprising:

a source of image data;

a light engine configured to project an image derived from the image data onto a surface;

an optical unit configured to record the reflection of the projected image; and

a processor configured to

determine a first average color for at least one subunit of the image data;

determine a second average color for a corresponding segment of the reflected image;

calculate a difference between the first and second average colors; and

calculate a correction factor that may be applied to reduce the calculated difference between respective average colors.

20. The display device of claim 19, where the image data source is an associated computer.

21. The display device of claim 19, where the optical unit is a camera.

22. The display device of claim 19, further including a memory connected to the processor, where the memory is configured to store the first average color.

23. A display device, comprising;

means for receiving image data;

means for projecting an image onto a surface to generate an image;

means for recording a reflection of the projected image;

means for calculating an average color for each of a plurality of subunits of the image data, determining an average color for each of a corresponding plurality of subunits of the reflected image, and determining a difference between the calculated average color and the determined average color for each subunit;

means for calculating a correction factor that may be applied to reduce the determined difference between the calculated and the determined average color;

means for applying the correction factor.

24. A storage medium readable by a processor, having embodied therein a program of commands executable by the processor to:

receive image data for a desired image;

project an image derived from the image data onto a surface to produce a reflected image;

calculate a desired average color for a subunit of the desired image;

determine an average color for a corresponding subunit of the reflected image;

determine a difference between the desired average color and the determined average color;

determine a correction factor configured to reduce the determined difference between the desired and determined average colors;

apply the correction factor to a projection value; and

project a corrected image using the corrected projection value.