Electronic camera with image sensor and rangefinding unit

• US 8,525,888 B2
• Filed: 01/15/2009
• Issued: 09/03/2013
• Est. Priority Date: 01/17/2008
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Abe, Hiroyuki
• Primary Examiner(s): VILLECCO, JOHN M
• Application Number:
  US12/811,734
• Publication Number:
  US 20100277609A1
• Time in Patent Office: 1,692 Days
• Field of Search: 348/208.16, 348/222.1, 348/229.1, 348/230.1, 348/231.6, 382/165, 382/209, 382/224, 382/225, 382/228, 396/137, 396/238, 396/242
• US Class Current: 348/208.16
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body
• CPC Class Codes: H04N 23/64 Computer-aided capture of images, e.g. transfer from script file into camera, check of taken image quality, advice or proposal for image composition or decision on when to take image
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

An electronic camera, includes an image sensor, a rangefinding means, an arithmetic operation means for calculating a characteristic quantities based upon at least either pixel density in an image obtained via the image sensor or rangefinding information obtained via the rangefinding means, a judgment means for judging a photographic scene based upon characteristic quantities calculated by the arithmetic operation means, and a control means for selecting camera settings in correspondence to the photographic scene having been judged.

Claims

1. An electronic camera, comprising:

an image sensor;

a rangefinding unit;

a first arithmetic operation unit that calculates a characteristic quantities based upon pixel density in an image obtained via the image sensor and rangefinding information obtained via the rangefinding unit;

a second arithmetic operation unit that selects a characteristic quantity group with characteristic quantities closest to the characteristic quantities calculated by the first arithmetic operation unit, among a plurality of characteristic quantity groups classified in advance in a space in which the characteristic quantities are expressed;

a third arithmetic operation unit that judges a photographic scene corresponding to the characteristic quantity group selected by the second arithmetic operation unit;

a control unit that selects camera settings in correspondence to the photographic scene having been judged; and

a storage unit that stores characteristic quantity variance/covariance information for each of the classified characteristic quantity groups, wherein;

the second arithmetic operation unit selects a characteristic quantity group corresponding to the variance/covariance information indicating a value closest to a characteristic quantity calculated within the space by the first arithmetic operation unit.

2. The electronic camera according to claim 1, further comprising:

the storage unit that stores mean value information indicating a mean value of characteristic quantities in each of the characteristic quantity groups having been classified, wherein;

the second arithmetic unit selects a characteristic quantity group corresponding to the mean value information indicating a value closest to a characteristic quantity calculated within the space by the first arithmetic operation unit.

3. The electronic camera according to claim 2, wherein:

characteristic quantities calculated for a plurality of sample images based upon pixel densities in the plurality of sample images and rangefinding information obtained while photographing the plurality of sample images are classified in advance in a space in which the characteristic quantities are expressed and the mean value information corresponding to each categorized characteristic quantity group is stored in the storage unit.

4. The electronic camera according to claim 1, wherein:

characteristic quantities for a plurality of sample images which are calculated based upon pixel densities of the plurality of sample images and rangefinding information obtained while photographing the plurality of sample images are classified in advance in a space in which the characteristic quantities are expressed, and the variance/covariance information corresponding to each classified characteristic quantity group is stored in the storage unit.

5. The electronic camera according to claim 1, wherein:

the first arithmetic operation unit calculates characteristic quantities based upon pixel density in an image obtained via the image sensor before a photographing instruction is issued and a rangefinding information obtained via the rangefinding unit before the photographing instruction is issued.

6. The electronic camera according to claim 1, wherein:

the first arithmetic operation unit calculates a characteristic quantity based upon pixel density over an entire image.

7. The electronic camera according to claim 1, wherein:

the first arithmetic operation unit calculates a plurality of characteristic quantities each based upon pixel density in one of various areas into which an image is divided.

8. The electronic camera according to claim 1, wherein:

the first arithmetic operation unit calculates a characteristic quantity based upon an extent of change in pixel density over an entire image.

9. The electronic camera according to claim 1, wherein:

the first arithmetic operation unit calculates a characteristic quantity based upon an extent of change in pixel density in a specific area of an image.

10. The electronic camera according to claim 1, wherein:

the first arithmetic operation unit calculates a characteristic quantity based upon rangefinding information corresponding to a subject.

11. The electronic camera according to claim 1, wherein:

the first arithmetic operation unit calculates a characteristic quantity based upon an extent of change in a rangefinding information for the an entire image.

12. The electronic camera according to claim 1, wherein:

the first arithmetic operation unit calculates a characteristic quantity based upon an extent of change in a rangefinding information in a specific area of an image.

13. An electronic camera, comprising:

an image sensor;

a rangefinding unit;

a first arithmetic operation unit that calculates a characteristic quantities based upon pixel density in an image obtained via the image sensor and rangefinding information obtained via the rangefinding unit;

a second arithmetic operation unit that selects a characteristic quantity group with characteristic quantities closest to the characteristic quantities calculated by the first arithmetic operation unit, among a plurality of characteristic quantity groups classified in advance in a space in which the characteristic quantities are expressed;

a third arithmetic operation unit that judges a photographic scene corresponding to the characteristic quantity group selected by the second arithmetic operation unit; and

a control unit that selects camera settings in correspondence to the photographic scene having been judged, wherein;

the first arithmetic operation unit calculates a plurality of (N) characteristic quantities based upon pixel density of images obtained via the image sensor and rangefinding informations obtained via the rangefinding unit;

the electronic camera further comprises a fourth arithmetic operation unit that executes characteristic quantity space conversion from a space in which the N characteristic quantities are expressed to a space in which the characteristic quantities of number less than N are expressed; and

the second arithmetic operation unit selects a characteristic quantity group with characteristic quantities closest to a characteristic quantities resulting from conversion executed by the fourth arithmetic operation unit among a plurality of characteristic quantity groups classified in advance in the space resulting from the characteristic quantity space conversion.

14. The electronic camera according to claim 13, further comprising:

a storage unit that stores mean value information indicating a mean value of characteristic quantities in the characteristic quantity group having been classified, wherein;

the second arithmetic unit selects a characteristic quantity group corresponding to the mean value information indicating a value closest to a characteristic quantity calculated by the fourth arithmetic operation unit within the space resulting from the characteristic quantity space conversion.

15. The electronic camera according to claim 14, wherein:

characteristic quantities for a plurality of sample images which are calculated based upon pixel densities in the plurality of sample images and rangefinding information obtained while photographing the plurality of sample images are classified in advance in a space resulting from the characteristic quantity space conversion in which the characteristic quantities are expressed and mean value information corresponding to each categorized characteristic quantity group is stored in the storage unit.

16. The electronic camera according to claim 13, further comprising:

a storage unit that stores characteristic quantity variance/covariance information for each of the classified characteristic quantity groups, wherein;

the second arithmetic operation unit selects a characteristic quantity group corresponding to the variance/covariance information indicating a value closest to a characteristic quantity calculated by the fourth arithmetic operation unit within the space resulting from the characteristic quantity space conversion.

17. The electronic camera according to claim 16, wherein:

characteristic quantities for a plurality of sample images which is calculated based upon pixel densities in the plurality of sample images and rangefinding information obtained while photographing the plurality of sample images are classified in advance in the space resulting from the characteristic quantity space conversion in which the characteristic quantities are expressed, and a variance/covariance information corresponding to each of the classified characteristic quantity group is stored in the storage unit.