LENS AND COLOUR FILTER ARRANGEMENT, SUPER-RESOLUTION CAMERA SYSTEM AND METHOD

• US 20120105691A1
• Filed: 09/22/2011
• Published: 05/03/2012
• Est. Priority Date: 11/03/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: SIDDIQUI, Muhammad, KAMM, Markus, WAQAS, Malik, MANZ, Manfred
• Granted Patent: US 9,137,503 B2
• Time in Patent Office: Days
• US Class Current: 348/280
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns
• CPC Class Codes: G06T 3/4069 by subpixel displacements
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A lens and colour filter assembly (100) contains lens units (110), wherein each lens unit (110) is assigned to a single-colour colour filter unit (120). The lens and colour filter assembly (100) may be combined with pixel units (230) such that a plurality of monochromatic, low-resolution images can be obtained, wherein the monochromatic images refer to shifted versions of the same image object. By a super-resolution technique comprising shift-compensation a mosaicked image is obtained which is then demosaiced. In the resultant image only few artefacts appear. Simple colour filter arrays allow a simplified fabrication process and provide less chromatic aberrations at less computational effort.

Claims

1. A lens and colour filter assembly (100) comprising

at least three lens units (110) and

at least three colour filter units (120), each colour filter unit (120) being assigned to one of the at least three lens units (110) and comprising a plurality of colour filter sections (125), wherein

the colour filter sections (125) have at least three different filter colours and each colour filter unit (120) is single-coloured.

2. The lens and colour filter assembly of claim 1, wherein

each lens unit (110) includes a micro-lens array comprising a plurality of micro-lenses (115) arranged in a matrix.

3. The lens and colour filter assembly of claim 1, wherein

each colour filter section (125) assigned to one of the lens units (110) is arranged such that light orthogonally incidenting on and passing through the one of the lens units (110) passes through the colour filter section (125).

4. The lens and colour filter assembly of claim 1, wherein

the number of lens units (110) is even and the lens units (110) are arranged in a matrix.

5. A camera system comprising

the lens and colour filter assembly (100) according to any of the preceding claims,

at least three pixel units (230), each pixel unit (230) assigned to one of the lens units (110) and comprising a plurality of pixel sensors (235) arranged in a matrix, wherein

each pixel sensor (235) is assigned to one of the colour filter sections (125).

6. The camera system according to claim 5, wherein

corresponding pixel sensors (235) in different pixel units (230) are shifted against each other.

7. The camera system according to claim 5, wherein

each pixel sensor (235) assigned to one of the colour filter sections (125) is arranged such that light orthogonally incidenting on and passing through the respective colour filter section (125) incidents on the pixel sensor (235).

8. The camera system according to claim 6, further comprising

a first calculator unit (240) configured to combine monochromatic low-resolution images obtained from the pixel units (210) to a mosaicked image by shift-compensating pixel values output by the pixel sensors (235) of the pixel units (230) in a regular manner.

9. The camera system according to claim 8, further comprising

a second calculator unit (250) configured to demosaic the polychromatic image by interpolating, for each filter colour, virtual pixel values on the basis of pixel values of neighbouring pixel sensors (235).

10. A method of operating a camera system, the method comprising

guiding light through at least three lens units (110), each lens unit (110) assigned to a single-colour colour filter unit (120), each single-colour colour filter unit (120) having another filter colour, to obtain at least three monochromatic low-resolution images of different colours, and

fusing the at least three monochromatic low-resolution images to a polychromatic high-resolution image.

11. The method of claim 10, wherein

the lens units (110) are arranged such that the at least three monochromatic low-resolution images are shifted to each other.

12. The method of claim 11, wherein fusing the at least three monochromatic low-resolution images to a polychromatic high-resolution image comprises

combining the monochromatic low-resolution images obtained from the pixel units (230) to a mosaicked polychromatic image by interdigitating pixel values output by the pixel sensors (235) of the pixel units (230), wherein the pixel values are shift-compensated.

13. The method of claim 12, wherein interdigitating the pixel values comprises

grouping pixel values output by corresponding pixel sensors (235) of all pixel units (230) to pixel clusters (987), wherein each pixel cluster (987) comprises a number of pixel values corresponding to the number of pixel units (230) and wherein each pixel value of each pixel cluster (987) is derived from another pixel unit (230), and

grouping the pixel clusters (987) in a matrix corresponding to the pixel matrix.

14. The method of claim 12, wherein fusing the at least three monochromatic low-resolution images to a polychromatic high-resolution image comprises

demosaicing the mosaicked polychromatic image by interpolating or estimating, for each filter colour, virtual pixel values on the basis of pixel values of neighbouring pixel sensors (235).

15. A method of manufacturing a lens and colour filter assembly (100), the method comprising

arranging at least three lens units (110) and at least three colour filter units (120), each colour filter unit (120) comprising a plurality of colour filter sections (125) with at least three different filter colours such that each colour filter unit (120) is monochromatic and assigned to one of the at least three lens units (110), and

providing calculator units (240, 250) for fusing the at least three monochromatic low-resolution images to a polychromatic high-resolution image.