Solid state imaging using a correction parameter for correcting a cross talk between adjacent pixels

• US 8,619,163 B2
• Filed: 09/01/2010
• Issued: 12/31/2013
• Est. Priority Date: 09/18/2009
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ogura, Masanori, Koizumi, Toru, Koizumi, Satoshi
• Primary Examiner(s): VU, NGOC YEN T
• Application Number:
  US12/874,119
• Publication Number:
  US 20110069210A1
• Time in Patent Office: 1,217 Days
• Field of Search: 348/243
• US Class Current: 348/242
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/62 Detection or reduction of noise due to excess charges produced by the exposure, e.g. smear, blooming, ghost image, crosstalk or leakage between pixels
• CPC Class Codes: H04N 9/646 for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters

Abstract

An image processing apparatus, for correcting a cross talk between adjacent pixels, includes: a memory unit for storing a correction parameter for reducing a cross talk signal leaked to an object pixel from an adjacent pixel, the correction parameter corresponding to a position of the object pixel; and a correcting unit for subtracting, based on the correction parameter stored in the memory unit, the cross talk signal from a pixel signal of the solid-state imaging apparatus correspondingly to a position of the pixel, wherein a number of the object pixel is at least two, and the at least two object pixels have different addresses in a horizontal direction, and different addresses in a vertical direction.

Claims

1. An image processing apparatus for a solid-state imaging apparatus comprising a plurality of pixels each including a photoelectric conversion element arranged two dimensionally in a matrix and a color filter of plural colors is arranged over a surface of the pixel, such that the image processing apparatus corrects a cross talk between adjacent pixels of different colors, wherein the image processing apparatus comprises:

a memory unit for storing a correction parameter for reduction a cross talk signal leaked to an object pixel from an adjacent pixel, the correction parameter corresponding to a position of the object pixel; and

a correcting unit for subtracting, based on the correction parameter stored in the memory unit, the cross talk signal from a pixel signal of the solid-state imaging apparatus correspondingly to a position of the pixel,

wherein a number of the object pixel is at least two, and the at least two object pixels have different addresses in a horizontal direction, and different addresses in a vertical direction, and

wherein, in moving image photographing mode, the correction parameter is derived from pixels in a column adjacent to the object pixel and pixels in a row adjacent to the object pixel, while,

in a mode different from the moving image photographing mode,

the correction parameter is derived from pixels adjacent to the object pixel in a column direction, pixels adjacent to the object pixel in a row direction, and pixels adjacent to the object pixel in an oblique direction.

2. The image processing apparatus according to claim 1, wherein

the correction parameter of a pixel in a center region of the solid-state imaging apparatus is different from the correction parameter of a pixel in a peripheral region of the solid-state imaging apparatus.

3. The image processing apparatus according to claim 1, wherein

the plurality of pixels is divided into a plurality of pixel regions, such that the memory unit stores the correction parameter of the pixels by pixel region, and

the correcting unit subtracts, based on the correction parameter of the pixels in one pixel region, the cross talk signal from the pixel signal of the pixels in the same one pixel region.

4. The image processing apparatus according to claim 1, wherein

the memory unit stores the correction parameter corresponding to a plurality of positions of the pixels, and

the correcting unit subtracts, based on the correction parameter corresponding to a nearest position of the pixel, the cross talk signal from the pixel signal.

5. The image processing apparatus according to claim 1, further comprising

a calculating unit for calculating the correction parameter based on a signal derived from an aperture pixel of the solid-state imaging apparatus and on a signal derived from a light shielded pixel adjacent to the aperture pixel, and then storing the correction parameter in the memory unit.

6. The image processing apparatus according to claim 1, wherein

the solid-state imaging apparatus includes a first aperture pixel, a second aperture pixel, a first light shielded pixel in the same row as a row along which the first aperture pixel is arranged, a second light shielded pixel in the same column as a column along which the first aperture pixel is arranged, a third light shielded pixel in the same row as a row along which the second aperture pixel is arranged, a fourth light shielded pixel in the same column as a column along which the second aperture pixel is arranged,

the memory unit stores the correction parameter of the first aperture pixel and the correction parameters of the first to fourth light shielded pixels, and

the correcting unit calculates the correction parameter of the second aperture pixel based on the correction parameter of the first aperture pixel and the correction parameters of the first to fourth light shielded pixels, and subtracts, based on the correction parameter of the correction parameter of the second aperture pixel, the cross talk signal from the pixel signal of the second aperture pixel.

7. The image processing apparatus according to claim 1, wherein

the correcting unit subtracts the cross talk signal from the pixel signal, according to at least one of an aperture value and a pupil distance controlled by an optical system of the solid-state imaging apparatus.

8. The image processing apparatus according to claim 1, wherein

the correcting unit adds, to the signal of the object pixel, the cross talk signal leaked to the object pixel from the adjacent pixel.

9. An imaging system comprising:

the image processing apparatus according to claim 1; and

a solid-state imaging apparatus comprising a plurality of pixels each including a photoelectric conversion element arranged two dimensionally in a matrix and a color filter of plural colors is arranged over a surface of the pixel.