Multi-image deblurring
View Patent ↗Embodiments of the invention describe a method for reducing a blur in an image of a scene. First, we acquire a set of images of the scene, wherein each image in the set of images includes an object having a blur associated with a point spread function (PSF) forming a set of point spread functions (PSFs), wherein the set of PSFs is suitable for null-filling operation. Next, we invert jointly the set of images and the set of PSFs to produce an output image having a reduced blur.
1. A method for reducing a blur in an image of a scene, comprising a processor for performing steps of the method, comprising the steps of:
acquiring a set of images of the scene with a single conventional camera, wherein each image in the set of images includes an object having a blur associated with a point spread function (PSF) forming a set of point spread functions (PSFs), wherein the set of PSFs is suitable for null-filling operation; and
inverting jointly the set of images and the set of PSFs to produce an output image having a reduced blur.
2. The method of claim 1 , further comprising:
acquiring the set of images with exposure times, which are non-integer multiples of each other.
3. The method of claim 2 , further comprising:
determining the exposure times such that a deconvolution operator is maximized.
4. The method of claim 2 , further comprising:
determining the exposure times such that the signal to noise is maximized.
5. The method of claim 1 , wherein the set of PSFs includes a first PSF, the first PSF at a particular frequency is zero, and a second PSF, wherein the second PSF at the particular frequency is not zero.
6. The method of claim 1 , further comprising:
acquiring the set of images using multiple cameras running at different frame rates.
7. The method of claim 1 , wherein the PSF is a motion PSF.
8. The method of claim 1 , wherein the inverting further comprising:
determining the output image according to
f
^
=
(
∑
k
=
1
N
A
k
T
A
k
)
-
1
(
∑
k
=
1
N
A
k
T
i
k
)
,
wherein {circumflex over (f)} is a vector describing the output image, A k is a circulant motion smear matrix for an image k, i k is a vector describing the blurred object, N is a number of images in the set of images, T is a transpose operator.
9. A method for reducing blur in an image, comprising a processor for performing steps of the method, comprising the steps of:
acquiring, with a single conventional camera, repetitively a set of images of a moving object with a set of exposures, wherein the exposures are non-integer multiples of each other;
estimating a point spread function (PSF) using motion vectors computed from images acquired with the same exposure forming a set of point spread functions (PSFs);
determining an alpha map for each image in the set of images;
removing a background contribution from the images using the alpha map; and
inverting jointly the set of images and the set of PSFs to produce an output image having a reduced blur.
10. The method of claim 9 , further comprising:
repeating the determining, the removing, and the inverting.
11. The method of claim 9 , wherein the acquiring is performed using a camera having an auto exposure bracketing.
12. The method of claim 9 , wherein for each image further comprising:
estimating a background of the image; and
generating a crude trimap by thresholding a difference between the image and the background.
13. The method of claim 9 , further comprising:
aligning the object in the set of images.
14. The method of claim 9 , further comprising:
refining a segmentation of the object for each motion line independently.
15. A camera configured for reducing blur in an image, comprising:
means for acquiring a set of images of a moving object with a single conventional camera, wherein each image is associated with a point spread function (PSF) forming a set of point spread functions (PSFs), wherein the set of PSFs is suitable for null-filling operation; and
means for inverting jointly the set of images and the set of PSFs to produce an output image having a reduced blur.
16. The camera of claim 15 , wherein the set of PSFs includes a first PSF, the first PSF at a particular frequency is zero, and a second PSF, wherein the second PSF at the particular frequency is not zero.
17. The camera of claim 15 , wherein the means for inverting further comprising:
means for determining the output image according to
f
^
=
(
∑
k
=
1
N
A
k
T
A
k
)
-
1
(
∑
k
=
1
N
A
k
T
i
k
)
,
wherein {circumflex over (f)} is a vector describing the output image, A k is a circulant motion smear matrix for an image k, i k is a vector describing the blurred object, N is a number of images in the set of images, T is a transpose operator.
18. The camera of claim 15 , further comprising:
means for estimating the set of PSFs.
19. The camera of claim 15 , further comprising:
means for segmenting the set of images.