Method for deblurring an image

• US 20060187308A1
• Filed: 02/23/2005
• Published: 08/24/2006
• Est. Priority Date: 02/23/2005
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Lim, Suk Hwan, Silverstein, D. Amnon
• Granted Patent: US 8,654,201 B2
• Time in Patent Office: Days
• US Class Current: 348/208.400
• CPC Class Codes: G06T 2207/20056 Discrete and fast Fourier transform, [DFT, FFT]
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6845 by combination of a plurality of images sequentially taken

Abstract

A method for deblurring an image. A first image is captured. A second image is captured, wherein the second image is more blurred and more exposed than the first image. The second image is deblurred based on the first image.

Claims

1. A method for deblurring an image, said method comprising:

capturing a first image;

capturing a second image, wherein said second image is more blurred and more exposed than said first image; and

deblurring said second image based on said first image.

2. The method as recited in claim 1 wherein said first image is captured using a shorter exposure time than said second image.

3. The method as recited in claim 1 wherein said first image is captured using a smaller aperture size than said second image.

4. The method as recited in claim 1 wherein said deblurring said second image based on said first image comprises:

generating a blur kernel based on said first image and said second image; and

deblurring said second image based on said blur kernel and said first image.

5. The method as recited in claim 4 wherein said generating said blur kernel comprises:

calculating an auto-correlation of said second image;

calculating a cross-correlation between said first image and said second image; and

deriving said blur kernel based on said auto-correlation and said cross-correlation.

6. The method as recited in claim 4 wherein said generating said blur kernel comprises:

calculating a Fourier transform of said first image;

calculating a Fourier transform of said second image;

calculating of the ratio of said Fourier transform of said second image to said Fourier transform of said first image; and

deriving the blur kernel based on an inverse Fourier transform of said ratio.

7. The method as recited in claim 4 wherein said deblurring said second image based on said blur kernel and said first image comprises deblurring said second image according to a regularized second order minimization by calculating a deblurred image that does not substantially deviate from said first image.

8. A computer-usable medium having computer-readable program code embodied therein for causing a computer system to perform a method for deblurring an image, said method comprising:

capturing a first image;

capturing a second image, wherein said second image is more blurred and more exposed than said first image; and

deblurring said second image based on said first image.

9. The computer-usable medium as recited in claim 8 wherein said first image is captured using a shorter exposure time than said second image.

10. The computer-usable medium as recited in claim 8 wherein said first image is captured using a smaller aperture size than said second image.

11. The computer-usable medium as recited in claim 8 wherein said deblurring said second image based on said first image comprises:

generating a blur kernel based on said first image and said second image; and

deblurring said second image based on said blur kernel and said first image.

12. The computer-usable medium as recited in claim 11 wherein said generating said blur kernel comprises:

calculating an auto-correlation of said second image;

calculating a cross-correlation between said first image and said second image; and

deriving said blur kernel based on said auto-correlation and said cross-correlation.

13. The computer-usable medium as recited in claim 11 wherein said generating said blur kernel comprises:

calculating a Fourier transform of said first image;

calculating a Fourier transform of said second image;

calculating of the ratio of said Fourier transform of said second image to said Fourier transform of said first image; and

deriving the blur kernel based on an inverse Fourier transform of said ratio.

14. The computer-usable medium as recited in claim 11 wherein said deblurring said second image based on said blur kernel and said first image comprises deblurring said second image according to a regularized second order minimization by calculating a deblurred image that does not substantially deviate from said first image.

15. A system for deblurring an image, said method comprising:

means for capturing a first image and a second image, wherein said second image is more blurred and more exposed than said first image; and

means for deblurring said second image based on said first image.

16. The system as recited in claim 15 wherein said first image is captured using a shorter exposure time than said second image.

17. The system as recited in claim 15 wherein said first image is captured using a smaller aperture size than said second image.

18. The system as recited in claim 15 wherein said means for deblurring said second image based on said first image comprises:

means for generating a blur kernel based on said first image and said second image; and

means for deblurring said second image based on said blur kernel and said first image.

19. The system as recited in claim 18 wherein said means generating said blur kernel comprises:

means for calculating an auto-correlation of second image;

means for calculating a cross-correlation between said first image and said second image; and

means for deriving said blur kernel based on said auto-correlation and said cross-correlation.

20. The system as recited in claim 18 wherein said means for generating said blur kernel comprises:

means for calculating a Fourier transform of said first image;

means for calculating a Fourier transform of said second image;

means for calculating of the ratio of said Fourier transform of said second image to said Fourier transform of said first image; and

means for deriving the blur kernel based on an inverse Fourier transform of the ratio.