Image processing apparatus and image processing method

• US 7,973,850 B2
• Filed: 09/26/2006
• Issued: 07/05/2011
• Est. Priority Date: 09/29/2005
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Ishiga, Kenichi
• Primary Examiner(s): Lam; Hung H
• Application Number:
  US11/992,480
• Publication Number:
  US 20090135267A1
• Time in Patent Office: 1,743 Days
• Field of Search: 348/222.1, 348/273, 348/335, 348/345
• US Class Current: 348/335
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"
• CPC Class Codes: H04N 25/611 Correction of chromatic aberration

Abstract

An image processing apparatus includes a discriminating unit that discriminates a color component originating in an image structure in an image captured through an optical system from a color component attributable to a chromatic aberration of the optical system, and a correction unit that corrects the color component attributable to the chromatic aberration of the optical system based upon discrimination results provided by the discriminating unit.

Claims

1. An image processing apparatus, comprising:

a discriminating unit that discriminates a color component originating in an image structure in an image captured through an optical system from a color component attributable to a chromatic aberration of the optical system, wherein;

the discriminating unit alters a sharpness of at least one color component of the captured image and discriminates the color component originating in the image structure in the captured image from the color component attributable to the chromatic aberration of the optical system based upon a difference in color response characteristics between at least two color components including the color component in correspondence to which the sharpness has been altered; and

if the color response characteristics between the two color components is represented by a monotonically decreasing function relative to a change in the sharpness, the discriminating unit determines that the color component in correspondence to which the sharpness has been altered is a color component originating in an image structure in the captured image.

2. An image processing apparatus according to claim 1, further comprising:

a correction unit that corrects the color component attributable to the chromatic aberration of the optical system based upon discrimination results provided by the discriminating unit.

3. An image processing apparatus, comprising:

a discriminating unit that discriminates a color component originating in an image structure in an image captured through an optical system from a color component attributable to a chromatic aberration of the optical system, wherein;

the discriminating unit alters a sharpness of at least one color component of the captured image and discriminates the color component originating in the image structure in the captured image from the color component attributable to the chromatic aberration of the optical system based upon a difference in color response characteristics between at least two color components including the color component in correspondence to which the sharpness has been altered; and

if the color response characteristics between the two color components is represented by a function with a minimal point relative to a change in the sharpness, the discriminating unit determines the color component in correspondence to which the sharpness has been altered is a color component containing a color component attributable to a chromatic aberration of the optical system.

4. An image processing apparatus according to claim 3, wherein:

when a value assumed at the minimal point of the color response characteristics is greater than a predetermined value, the discriminating unit determines the color component in correspondence to which the sharpness has been altered is a color component originating in an image structure in the captured image.

5. An image processing apparatus according to claim 3, further comprising:

a correction unit that corrects the color component attributable to the chromatic aberration of the optical system based upon discrimination results provided by the discriminating unit.

6. An image processing apparatus, comprising:

a discriminating unit that discriminates a color component originating in an image structure in an image captured through an optical system from a color component attributable to a chromatic aberration of the optical system, wherein;

the discriminating unit alters a sharpness of at least one color component of the captured image and discriminates the color component originating in the image structure in the captured image from the color component attributable to the chromatic aberration of the optical system based upon a difference in color response characteristics between at least two color components including the color component in correspondence to which the sharpness has been altered; and

the discriminating unit alters the sharpness of at least one color component so that a difference between levels of definition of at least two color components including the color component in correspondence to which the sharpness is altered is greater than a difference between levels of definition of color component attributable to a chromatic aberration of the optical system.

7. An image processing apparatus according to claim 6, further comprising:

a correction unit that corrects the color component attributable to the chromatic aberration of the optical system based upon discrimination results provided by the discriminating unit.

8. An image processing apparatus, comprising:

a discriminating unit that discriminates a color component originating in an image structure in an image captured through an optical system from a color component attributable to a chromatic aberration of the optical system, wherein;

the discriminating unit alters a sharpness of at least one color component of the captured image and discriminates the color component originating in the image structure in the captured image from the color component attributable to the chromatic aberration of the optical system based upon a difference in color response characteristics between at least two color components including the color component in correspondence to which the sharpness has been altered; and

there is further provided a color response characteristics correction unit that corrects the color response characteristics in correspondence to a level of initial saturation in the captured image before the sharpness is altered for the one color component.

9. An image processing apparatus according to claim 8, further comprising:

a correction unit that corrects the color component attributable to the chromatic aberration of the optical system based upon discrimination results provided by the discriminating unit.

10. An image processing apparatus, comprising:

a discriminating unit that discriminates a color component originating in an image structure in an image captured through an optical system from a color component attributable to a chromatic aberration of the optical system, wherein;

the discriminating unit alters a sharpness of at least one color component of the captured image and discriminates the color component originating in the image structure in the captured image from the color component attributable to the chromatic aberration of the optical system based upon a difference in color response characteristics between at least two color components including the color component in correspondence to which the sharpness has been altered; and

there is further provided a color response characteristics correction unit that corrects the color response characteristics when a relationship between levels indicated by values assigned to the two color components relative to each other become inverted after the sharpness for the one color component is altered.

11. An image processing apparatus according to claim 10, further comprising:

a correction unit that corrects the color component attributable to the chromatic aberration of the optical system based upon discrimination results provided by the discriminating unit.