Imaging device and camera body

• US 8,199,243 B2
• Filed: 04/24/2009
• Issued: 06/12/2012
• Est. Priority Date: 04/28/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Miyazaki, Kyoichi, Honjo, Kenichi, Kimura, Yuichi, Sasaki, Shogo, Murayama, Masato
• Primary Examiner(s): Laballe, Clayton E
• Assistant Examiner(s): Fenwick, Warren
• Application Number:
  US12/429,453
• Publication Number:
  US 20090268078A1
• Time in Patent Office: 1,145 Days
• Field of Search: 348/335, 348/208.4, 348/208.16, 348/208.99, 396/52, 396/55
• US Class Current: 348/335
• CPC Class Codes: G03B 13/00 Viewfinders; Focusing aids for cameras; Means for focusing for cameras; Autofocus systems for cameras
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"

Abstract

A digital camera comprises an interchangeable lens unit and a camera body. The interchangeable lens unit is provided to form an optical image of a subject. A flash memory is configured to hold a correction coefficient table used to electrically correct distortion produced by the optical system. The camera body has a CCD image sensor, a correction coefficient acquisition part, an operation part, and a correction processor. The correction coefficient acquisition part is configured to acquire the correction coefficient table held in the flash memory. The operation part is configured to produce correction data by performing an interpolation operation or an extrapolation operation on the information obtained from the correction coefficient table. The correction processor is configured to correct distortion in the image data on the basis of information produced by the operation part.

Claims

1. An imaging device for acquiring image data for a subject, comprising:

an interchangeable lens unit having an optical system provided to form an optical image of the subject, and a first holding part configured to hold first correction information used to electrically correct distortion produced by the optical system; and

a camera body having an image acquisition part configured to convert the optical image into image data, a correction information acquisition part configured to acquire the first correction information held in the first holding part, an operation part configured to produce second correction information by performing an interpolation operation or an extrapolation operation on the first correction information, and a distortion corrector configured to correct distortion in the image data on the basis of the second correction information, wherein

the first correction information includes a plurality of correction coefficients used to correct the distortion in the image data,

the camera body has a correction information selector configured to select the correction coefficients from the first correction information as selected correction coefficient group, and

the operation part is configured to produce the second correction information on the basis of the selected correction coefficient group.

2. The imaging device according to claim 1, wherein

the distortion corrector is configured to correct distortion by using a magnifying power correction value for keeping the corrected image data at or above a specific size.

3. The imaging device according to claim 1, wherein

the first holding part is configured to hold first identification information used to identify the interchangeable lens unit,

the camera body has an identification information acquisition part capable of acquiring the first identification information held in the first holding part as a second identification information, a second holding part that can associate and hold the second identification information and the first correction information corresponding to the second identification information, and a comparator configured to compare the first identification information with the second identification information, and

when the comparator determines that the first identification information held in the first holding part matches the second identification information held in the second holding part, the distortion corrector corrects the distortion by using the first correction information held in the second holding part and corresponding to the second identification information.

4. The imaging device according to claim 1, further comprising

an accessory unit mounted between the interchangeable lens unit and the camera body, and having a third holding part configured to hold third correction information used to correct the distortion, wherein

the correction information acquisition part is able to acquire the third correction information held in the third holding part, and

the distortion corrector is configured to correct the distortion on the basis of the first correction information and the third correction information.

5. The imaging device according to claim 1, wherein

the optical system is capable of changing the focal distance, and has a focus lens arranged to adjust the focal state of the optical image, and

the first correction information includes a correction coefficient table, in which are arranged the plurality of correction coefficients used to correct the distortion on the basis of zoom information related to the focal distance of the optical system and focus information related to the focal state of the optical image.

6. The imaging device according to claim 5, wherein

the distortion corrector is configured to correct distortion by using a magnifying power correction value for keeping the corrected image data at or above a specific size.

7. The imaging device according to claim 5, wherein

the first holding part is configured to hold first identification information used to identify the interchangeable lens unit,

the camera body has an identification information acquisition part capable of acquiring the first identification information held in the first holding part as a second identification information, a second holding part that can associate and hold the second identification information and the first correction information corresponding to the second identification information, and a comparator configured to compare the first identification information with the second identification information, and

when the comparator determines that the first identification information held in the first holding part matches the second identification information held in the second holding part, the distortion corrector corrects the distortion by using the first correction information held in the second holding part and corresponding to the second identification information.

8. The imaging device according to claim 5, further comprising

an accessory unit mounted between the interchangeable lens unit and the camera body, and having a third holding part configured to hold third correction information used to correct the distortion, wherein

the correction information acquisition part is able to acquire the third correction information held in the third holding part, and

the distortion corrector is configured to correct the distortion on the basis of the first correction information and the third correction information.

9. The imaging device according to claim 5, wherein

the interchangeable lens unit has a first detector configured to acquire the zoom information as a detected zoom information, and a second detector configured to acquire the focus information as a detected focus information,

the camera body has a first information acquisition part configured to acquire the detected zoom information from the first detector, and a second information acquisition part configured to acquire the detected focus information from the first detector, and

the correction information selector configured to select the correction coefficients corresponding to the detected zoom information and the detected focus information from the second correction information.

10. The imaging device according to claim 9, wherein

the correction coefficient table includes a plurality of correction ratios arranged along with the plurality of correction coefficients on the basis of the zoom information and the focus information and used to adjust the proportion in which the correction coefficients act during correction of the distortion.

11. The imaging device according to claim 9, wherein

the distortion corrector is configured to correct distortion by using a magnifying power correction value for keeping the corrected image data at or above a specific size.

12. The imaging device according to claim 9, wherein

the first holding part is configured to hold first identification information used to identify the interchangeable lens unit,

the camera body has an identification information acquisition part capable of acquiring the first identification information held in the first holding part as a second identification information, a second holding part that can associate and hold the second identification information and the first correction information corresponding to the second identification information, and a comparator configured to compare the first identification information with the second identification information, and

when the comparator determines that the first identification information held in the first holding part matches the second identification information held in the second holding part, the distortion corrector corrects the distortion by using the first correction information held in the second holding part and corresponding to the second identification information.

13. The imaging device according to claim 9, further comprising

an accessory unit mounted between the interchangeable lens unit and the camera body, and having a third holding part configured to hold third correction information used to correct the distortion, wherein

the correction information acquisition part is able to acquire the third correction information held in the third holding part, and

the distortion corrector is configured to correct the distortion on the basis of the first correction information and the third correction information.

14. The imaging device according to claim 9, wherein

the distortion corrector is configured to correct distortion by using a magnifying power correction value for keeping the corrected image data at or above a specific size.

15. The imaging device according to claim 9, wherein

the first holding part is configured to hold first identification information used to identify the interchangeable lens unit,

the camera body has an identification information acquisition part capable of acquiring the first identification information held in the first holding part as a second identification information, a second holding part that can associate and hold the second identification information and the first correction information corresponding to the second identification information, and a comparator configured to compare the first identification information with the second identification information, and

when the comparator determines that the first identification information held in the first holding part matches the second identification information held in the second holding part, the distortion corrector corrects the distortion by using the first correction information held in the second holding part and corresponding to the second identification information.

16. An imaging device for acquiring image data for a subject, comprising:

an interchangeable lens unit having an optical system provided to form an optical image of the subject, and a first holding part configured to hold first correction information used to electrically correct distortion produced by the optical system; and

a camera body having an image acquisition part configured to convert the optical image into image data, a correction information acquisition part configured to acquire the first correction information held in the first holding part, an operation part configured to produce second correction information by performing an interpolation operation or an extrapolation operation on the first correction information, and a distortion corrector configured to correct distortion in the image data on the basis of the second correction information,

wherein

the distortion corrector is configured to correct distortion by using a magnifying power correction value for keeping the corrected image data at or above a specific size.

17. An imaging device for acquiring image data for a subject, comprising:

an interchangeable lens unit having an optical system provided to form an optical image of the subject, and a first holding part configured to hold first correction information used to electrically correct distortion produced by the optical system; and

a camera body having an image acquisition part configured to convert the optical image into image data, a correction information acquisition part configured to acquire the first correction information held in the first holding part, an operation part configured to produce second correction information by performing an interpolation operation or an extrapolation operation on the first correction information, and a distortion corrector configured to correct distortion in the image data on the basis of the second correction information,

wherein

the first holding part is configured to hold first identification information used to identify the interchangeable lens unit,

the camera body has an identification information acquisition part capable of acquiring the first identification information held in the first holding part as a second identification information, a second holding part that can associate and hold the second identification information and the first correction information corresponding to the second identification information, and a comparator configured to compare the first identification information with the second identification information, and

when the comparator determines that the first identification information held in the first holding part matches the second identification information held in the second holding part, the distortion corrector corrects the distortion by using the first correction information held in the second holding part and corresponding to the second identification information.

18. An imaging device for acquiring image data for a subject, comprising:

an interchangeable lens unit having an optical system provided to form an optical image of the subject and a first holding part configured to hold first correction information used to electrically correct distortion produced by the optical system;

a camera body having an image acquisition part configured to convert the optical image into image data, a correction information acquisition part configured to acquire the first correction information held in the first holding part, an operation part configured to produce second correction information by performing an interpolation operation or an extrapolation operation on the first correction information, and a distortion corrector configured to correct distortion in the image data on the basis of the second correction information; and

an accessory unit mounted between the interchangeable lens unit and the camera body, and having a third holding part configured to hold third correction information used to correct the distortion, wherein

the correction information acquisition part is able to acquire the third correction information held in the third holding part, and

the distortion corrector is configured to correct the distortion on the basis of the first correction information and the third correction information.

19. A camera body used in an imaging device for acquiring image data of a subject along with an interchangeable lens unit, comprising:

an image acquisition part configured to convert an optical image of the subject into image data;

a correction information acquisition part configured to acquire from the interchangeable lens unit first correction information used to electrically correct distortion produced by the interchangeable lens unit;

an operation part configured to produce second correction information by performing an interpolation operation or an extrapolation operation on the first correction information; and

a distortion corrector configured to correct distortion in the image data on the basis of the second correction information, wherein

the first correction information includes a plurality of correction coefficients used to correct the distortion in the image data,

the camera body has a correction information selector configured to select the correction coefficients from the first correction information as selected correction coefficient group, and

the operation part is configured to produce the second correction information on the basis of the selected correction coefficient group.

20. A camera body used in an imaging device for acquiring image data of a subject along with an interchangeable lens unit, comprising:

an interface for receiving and transmitting data to and from the interchangeable lens unit;

a controller coupled to the interface; and

a memory coupled to the controller, the memory including instructions for configuring the controller to;

convert an optical image received among the data from the interface into image data;

acquire first correction information stored in a portion of the memory, the first correction information including a plurality of correction coefficients used to correct distortion in the image data;

select the correction coefficients from the first correction information as a selected correction coefficient group

produce second correction information by performing an interpolation operation or an extrapolation operation on the first correction information on the basis of the selected correction coefficient group; and

correct distortion in the image data on based on the second correction information.