Method and system for processing an image

• US 10,565,716 B2
• Filed: 02/20/2018
• Issued: 02/18/2020
• Est. Priority Date: 06/10/2014
• Status: Active Grant

• Current Assignee: Ramot at Tel Aviv University Limited (Tel Aviv University)
• Original Assignee: Ramot at Tel Aviv University Limited (Tel Aviv University)
• Inventors: Haim, Harel, Marom, Emanuel, Bronstein, Alex
• Primary Examiner(s): Wu, Jingge
• Application Number:
  US15/899,394
• Publication Number:
  US 20180174315A1
• Time in Patent Office: 728 Days
• CPC Class Codes: G06T 2200/21 involving computational photography
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/10141 Special mode during image acquisition
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• 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: G06T 7/50 Depth or shape recovery
• CPC Class Codes: G06T 7/571 from focus

Abstract

A method of processing an image is disclosed. The method comprises decomposing the image into a plurality of channels, each being characterized by a different depth-of-field, and accessing a computer readable medium storing an in-focus dictionary defined over a plurality of dictionary atoms, and an out-of-focus dictionary defined over a plurality of sets of dictionary atoms, each set corresponding to a different out-of-focus condition. The method also comprises computing one or more sparse representations of the decomposed image over the dictionaries.

Claims

1. A method of processing an image, comprising:

decomposing the image into a plurality of channels, each being characterized by a different depth-of-field;

accessing a computer readable medium storing an in-focus dictionary defined over a plurality of dictionary atoms, and an out-of-focus dictionary defined over a plurality of sets of dictionary atoms, each set corresponding to a different out-of-focus condition, said out-of-focus dictionary comprising a plurality of sub-dictionaries, each being characterized by a defocus parameter, wherein different sub-dictionaries correspond to different values of said defocus parameter; and

expressing the image as a combination of atoms of said dictionaries.

2. The method of claim 1, wherein said decomposing is done optically at the time of image capture.

3. The method of claim 1, wherein said decomposing is done by digital image processing.

4. The method according to claim 1, wherein said sparse representation is computed such that different region of said image have different defocus conditions.

6. The method according to claim 1, further comprising constructing a depth map of the scene, based on said sparse representation.

7. The method according to claim 6, further comprising re-focusing at least a portion of said image based on said depth map.

8. The method according to claim 6, further comprising generating a three-dimensional image based on said depth map.

9. The method according to claim 6, wherein said depth map is constructed based on a single image frame.

10. The method according to claim 1, wherein said plurality of channels is a plurality of color channels.

11. The method according to claim 1, comprising dividing said image into a plurality of patches, wherein said expressing is executed for each patch separately.

12. The method according to claim 1, wherein each patch of at least a few of said patches overlaps with at least one adjacent patch.

5. A method of imaging, comprising:

capturing an image of a scene using an imaging device having an optical mask selected to optically decompose said image into a plurality of channels, each being characterized by a different depth-dependence of a spatial frequency response of said imaging device;

accessing a computer readable medium storing an in-focus dictionary defined over a plurality of dictionary atoms, and an out-of-focus dictionary defined over a plurality of sets of dictionary atoms, each set corresponding to a different out-of-focus condition, said out-of-focus dictionary comprising a plurality of sub-dictionaries, each being characterized by a defocus parameter, wherein different sub-dictionaries correspond to different values of said defocus parameter; and

expressing the image as a combination of atoms of said dictionaries.

13. An imaging system, comprise:

an imaging device having an optical mask and being configured for capturing an image of a scene, wherein said optical mask is selected to optically decompose said image into a plurality of channels, each being characterized by a different depth-dependence of a spatial frequency response of said imaging device;

a computer readable medium storing an in-focus dictionary defined over a plurality of dictionary atoms, and an out-of-focus dictionary defined over a plurality of sets of dictionary atoms, each set corresponding to a different out-of-focus condition, said out-of-focus dictionary comprising a plurality of sub-dictionaries, each being characterized by a defocus parameter, wherein different sub-dictionaries correspond to different values of said defocus parameter; and

a data processor configured for accessing said computer readable medium and expressing the image as a combination of atoms of said dictionaries.

14. A portable device, comprising the imaging system of claim 13.

15. The portable device of claim 14, being selected from the group consisting of a cellular phone, a smartphone, a tablet device, a mobile digital camera, a wearable camera, a personal computer, a laptop, a portable media player, a portable gaming device, a portable digital assistant device, and a portable navigation device.

16. The imaging system according to claim 13, wherein said data processor is configured for constructing a depth map of the scene, based on said sparse representation.

17. The imaging system according to claim 16, wherein said data processor is configured for re-focusing at least a portion of said image based on said depth map.

18. The imaging system according to claim 16, wherein said data processor is configured for generating a three-dimensional image based on said depth map.

19. The imaging system according to claim 16, wherein said depth map is constructed based on a single image frame.