IMAGE PROCESSING DEVICE, IMAGE PROCESSING METHOD, AND PROGRAM

• US 20120002113A1
• Filed: 04/28/2011
• Published: 01/05/2012
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: KINOSHITA, Hiroyuki, IRISAWA, Gentaro, NISHIO, Kenichi, KANG, Hyongmyong, HASHINO, Tsukasa, KATO, Takuya, MINATO, Atsuo
• Granted Patent: US 8,730,357 B2
• Time in Patent Office: Days
• US Class Current: 348/624
• CPC Class Codes: H04N 23/10 for generating image signals from different wavelengths
• CPC Class Codes: H04N 23/12 with one sensor only
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/611 Correction of chromatic aberration

Abstract

An image processing method includes the steps of calculating, with respect to a processing-target pixel in an input image signal, a concentric aberration correction amount for concentric aberration that is a component of magnification chromatic aberration, the concentric aberration causing a color shift to occur in a concentric manner from the center of an image, calculating, with respect to the processing-target pixel, a uniform aberration correction amount for uniform aberration that is a component of magnification chromatic aberration, the uniform aberration causing a color shift direction and a color shift amount to uniformly occur on a whole image, and correcting a pixel value of the processing-target pixel on the basis of the calculated concentric aberration correction amount and the calculated uniform aberration correction amount.

Claims

1. An image processing device comprising:

a concentric aberration correction amount calculation unit configured to calculate, with respect to a processing-target pixel in an input image signal, a concentric aberration correction amount for concentric aberration that is a component of magnification chromatic aberration, the concentric aberration causing a color shift to occur in a concentric manner from the center of an image;

a uniform aberration correction amount calculation unit configured to calculate, with respect to the processing-target pixel, a uniform aberration correction amount for uniform aberration that is a component of magnification chromatic aberration, the uniform aberration causing a color shift direction and a color shift amount to uniformly occur on a whole image; and

a pixel value correction unit configured to correct a pixel value of the processing-target pixel on the basis of the calculated concentric aberration correction amount and the calculated uniform aberration correction amount.

2. The image processing device according to claim 1, further comprising:

a concentric aberration correction data holding unit configured to hold, as concentric aberration correction amount data, the concentric aberration correction amount corresponding to each concentric aberration condition including at least a combination of a color of light and an image height; and

a uniform aberration correction data holding unit configured to hold, as uniform aberration correction amount data, the uniform aberration correction amount corresponding to each concentric aberration condition including at least a color of light, wherein

the concentric aberration correction amount calculation unit selects the concentric aberration correction amount data corresponding to the concentric aberration condition to which the processing-target pixel corresponds, and calculates the concentric aberration correction amount using the selected concentric aberration correction amount data, and

the uniform aberration correction amount calculation unit selects the uniform aberration correction amount data corresponding to the uniform aberration condition to which the processing-target pixel corresponds, and calculates the uniform aberration correction amount using the selected uniform aberration correction amount data.

3. The image processing device according to claim 2, wherein

the concentric aberration correction amount data indicates a correction amount corresponding to a color shift amount in an image height direction, which occurs in response to the concentric aberration condition, and

the uniform aberration correction amount data indicates a correction amount corresponding to a color shift amount and a color shift direction which occur in response to the uniform aberration condition.

4. The image processing device according to claim 2, wherein

the uniform aberration correction amount data includes a horizontal direction correction amount obtained in response to a horizontal direction color shift amount measured in a predetermined region as a target, the predetermined region including a virtual vertical line passing through a central portion of a captured image, and a vertical direction correction amount obtained in response to a vertical direction color shift amount measured in a predetermined region as a target, the predetermined region including a virtual horizontal line passing through the central portion of the captured image.

5. The image processing device according to claim 2, wherein

the concentric aberration correction amount data indicates a correction amount corresponding to the concentric aberration condition including a combination of a color of light, an image height, and predetermined lens control information used when an image to be a source of the input image signal is captured, and

the uniform aberration correction amount data indicates a correction amount corresponding to the uniform aberration condition including a combination of a color of light and predetermined lens control information used when an image of the input image signal is captured.

6. The image processing device according to claim 5, wherein

the lens control information is information indicating a control state of each of one or more predetermined movable portions in a lens unit.

7. The image processing device according to claim 2, wherein

the concentric aberration correction amount data is calculated from simulation based on a characteristic of a lens.

8. The image processing device according to claim 1, further comprising:

a uniform aberration component-associated edge detection unit configured to detect an edge corresponding to the uniform aberration from the input image signal; and

a concentric aberration component-associated edge detection unit configured to detect an edge corresponding to the concentric aberration from the input image signal a pixel value of which has been corrected by the pixel value correction unit on the basis of the uniform aberration correction amount, wherein

the uniform aberration correction amount calculation unit calculates a uniform aberration correction amount for the processing-target pixel on the basis of a color shift amount occurring, owing to uniform aberration, in each edge detected by the uniform aberration component-associated edge detection unit,

the concentric aberration correction amount calculation unit calculates a concentric aberration correction amount for the processing-target pixel on the basis of a color shift amount occurring, owing to concentric aberration, in each edge detected by the concentric aberration component-associated edge detection unit, and

the pixel value correction unit corrects, on the basis of the concentric aberration correction amount, a pixel value of the processing-target pixel that has been corrected on the basis of the uniform aberration correction amount.

9. The image processing device according to claim 8, wherein

the uniform aberration component-associated edge detection unit detects an edge in a vertical direction in the vicinity of an image portion in a horizontal radial direction in an image of the input image signal, and detects an edge in a horizontal direction in the vicinity of an image portion in a vertical radial direction in an image of the input image signal, and

the concentric aberration component-associated edge detection unit detects an edge in a radial direction in the vicinity of an image portion in each of at least one predetermined radial direction in an image of the input image signal.

10. The image processing device according to claim 8, wherein

each of the uniform aberration component-associated edge detection unit and the concentric aberration component-associated edge detection unit detects, with respect to each detected edge, a type of a change direction of a pixel value of the edge,

the uniform aberration correction amount calculation unit calculates the uniform aberration correction amount using a statistical result relating to a type of a change direction of a pixel value, detected by the uniform aberration component-associated edge detection unit, and

the concentric aberration correction amount calculation unit calculates the concentric aberration correction amount using a statistical result relating to a type of a change direction of a pixel value with respect to each detected edge, detected by the concentric aberration component-associated edge detection unit.

11. The image processing device according to claim 1, further comprising:

a concentric aberration correction data holding unit configured to hold, as concentric aberration correction amount data, the concentric aberration correction amount corresponding to each concentric aberration condition including at least a combination of a color of light and an image height; and

a uniform aberration component-associated edge detection unit configured to detect an edge corresponding to the uniform aberration from the input image signal, wherein

the concentric aberration correction amount calculation unit selects the concentric aberration correction amount data corresponding to the concentric aberration condition to which the processing-target pixel corresponds, and calculates the concentric aberration correction amount using the selected concentric aberration correction amount data, and

the uniform aberration correction amount calculation unit calculates a uniform aberration correction amount for the processing-target pixel on the basis of a color shift amount occurring, owing to uniform aberration, in each edge detected by the uniform aberration component-associated edge detection unit.

12. An image processing method comprising the steps of:

calculating, with respect to a processing-target pixel in an input image signal, a concentric aberration correction amount for concentric aberration that is a component of magnification chromatic aberration, the concentric aberration causing a color shift to occur in a concentric manner from the center of an image;

calculating, with respect to the processing-target pixel, a uniform aberration correction amount for uniform aberration that is a component of magnification chromatic aberration, the uniform aberration causing a color shift direction and a color shift amount to uniformly occur on a whole image; and

correcting a pixel value of the processing-target pixel on the basis of the calculated concentric aberration correction amount and the calculated uniform aberration correction amount.

13. A program for causing a computer to execute:

a concentric aberration correction amount calculation procedure for calculating, with respect to a processing-target pixel in an input image signal, a concentric aberration correction amount for concentric aberration that is a component of magnification chromatic aberration, the concentric aberration causing a color shift to occur in a concentric manner from the center of an image;

a uniform aberration correction amount calculation procedure for calculating, with respect to the processing-target pixel, a uniform aberration correction amount for uniform aberration that is a component of magnification chromatic aberration, the uniform aberration causing a color shift direction and a color shift amount to uniformly occur on a whole image; and

a pixel value correction procedure for correcting a pixel value of the processing-target pixel on the basis of the calculated concentric aberration correction amount and the calculated uniform aberration correction amount.