Electronic still imaging apparatus and method having function for acquiring synthesis image having wide-dynamic range

• US 20040095472A1
• Filed: 04/15/2003
• Published: 05/20/2004
• Est. Priority Date: 04/18/2002
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Higuchi, Masayu, Yoshida, Hideaki
• Granted Patent: US 7,379,094 B2
• Time in Patent Office: Days
• US Class Current: 348/208.12
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors

Abstract

A still imaging apparatus includes an imaging device, a storage device, and a positional displacement correcting device. The imaging device continuously executes imaging of a plurality of times with exposure amounts different from each other. The storage device stores a plurality of original images acquired by the imaging of the plurality of times executed by the imaging device. The positional displacement detecting device detects positional displacements of common objects included in the plurality of original images stored in the storage device and stores a plurality of corrected original images whose positional displacements are corrected based on detected positional displacements in the storage device through updating.

Claims

1. An electronic still imaging apparatus comprising:

an imaging device which continuously executes imaging of a plurality of times with different exposure amounts different from each other;

a storage device which stores a plurality of original images acquired by the imaging of the plurality of times executed by the imaging device, respectively; and

a positional displacement correcting device which detects positional displacements of common objects included in the plurality of original images stored in the storage device and stores a plurality of corrected original images whose positional displacements are corrected based on detected positional displacements in the storage device through updating.

2. An electronic still imaging apparatus according to claim 1, wherein the positional displacement correcting device detects the positional displacements based on a calculation of a two-dimensional correlation of the common objects included in the plurality of original images.

3. An electronic still imaging apparatus according to claim 1, wherein the positional displacement correcting device detects the positional displacements by determining shift vectors of the common objects included in said plurality of original images.

4. An electronic still imaging apparatus according to claim 1, wherein the positional displacement correcting device comprises a blur sensor device which detects a blur amount of the electronic still imaging apparatus and detects the positional displacements based on a blur sensor output from the blur sensor device.

5. An electronic still imaging apparatus comprising:

a luminance range detecting device which discriminates a luminance range of a picture to be imaged in a plurality of stages;

an imaging device which continuously executes imaging of a plurality of times with exposure amounts different from each other according to a luminance range discriminated by the luminance range detecting device;

a storage device which stores a plurality of original images acquired by the imaging of the plurality of times executed by the imaging device, respectively; and

a synthesizing device which outputs an image signal whose dynamic range is expanded by synthesizing the plurality of original images stored in the storage device.

6. An electronic still imaging apparatus according to claim 5, wherein the luminance range detecting device detects the luminance range based on histogram data of brightness of an imaging signal.

7. An electronic still imaging apparatus according to claim 5, wherein the luminance range detecting device determines a weighed average value of object luminance from an imaging signal acquired under an exposure condition according to a result of preliminary imaging and detects the luminance range based on the weighed average value.

8. An electronic still imaging method comprising:

detecting a luminance range in a picture to be imaged according to a result of preliminary imaging;

determining a number of times of an exposure which is executed by changing an exposure amount according to a detected luminance range;

storing a plurality of original images acquired by sequentially executing the exposure of a determined number of times, respectively;

detecting positional displacements of common objects included in stored plurality of original images and storing a plurality of corrected original images whose positional displacements are corrected based on detected positional displacements through updating; and

outputting an image signal whose dynamic range is expanded by synthesizing the plurality of corrected original images stored through updating.

9. An electronic still imaging method according to claim 8, wherein the luminance range is detected by analyzing a histogram.

10. An electronic still imaging method according to claim 8, wherein the luminance range is detected by detecting a shift vectors.

11. An electronic still imaging method of outputting an image signal whose dynamic range is expanded by synthesizing partial image signals in respective image signals acquired by continuously executing imaging of a plurality of times with exposure amounts different from each other, comprising:

detecting a luminance range of an object and appropriately setting a number of times of the imaging executed the plurality of times according to a detected luminance range of the object; and

detecting the positional displacements of the object in imaging signals acquired by the imaging executed the plurality of times and correcting and synthesizing the imaging signals of the plurality of times based on detected positional displacements.

12. An electronic still imaging apparatus comprising:

imaging means for continuously executing imaging of a plurality of times with different exposure amounts different from each other;

storage means for storing a plurality of original images acquired by the imaging of the plurality of times executed by the imaging means, respectively; and

positional displacement correcting means for detecting positional displacements of common objects included in the plurality of original images stored in the storage means and storing a plurality of corrected original images whose positional displacements are corrected based on detected positional displacements in the storage means through updating.

13. An electronic still imaging apparatus according to claim 12, wherein the positional displacement correcting means detects the positional displacements based on a calculation of a two-dimensional correlation of the common objects included in the plurality of original images.

14. An electronic still imaging apparatus according to claim 12, wherein the positional displacement correcting means detects the positional displacements by determining shift vectors of the common objects included in said plurality of original images.

15. An electronic still imaging apparatus according to claim 12, wherein the positional displacement correcting means comprises blur sensor means for detecting a blur amount of the electronic still imaging apparatus and detects the positional displacements based on a blur sensor output from the blur sensor means.

16. An electronic still imaging apparatus comprising:

luminance range detecting means for discriminating a luminance range of a picture to be imaged in a plurality of stages;

imaging means for continuously executing imaging of a plurality of times with exposure amounts different from each other according to a luminance range discriminated by the luminance range detecting means;

storage means for storing a plurality of original images acquired by the imaging of the plurality of times executed by the imaging means, respectively; and

synthesizing means for outputting an image signal whose dynamic range is expanded by synthesizing the plurality of original images stored in the storage means.

17. An electronic still imaging apparatus according to claim 16, wherein the luminance range detecting means detects the luminance range based on histogram data of brightness of an imaging signal.

18. An electronic still imaging apparatus according to claim 16, wherein the luminance range detecting means determines a weighed average value of object luminance from an imaging signal acquired under an exposure condition according to a result of preliminary imaging and detects the luminance range based on the weighed average value.

19. An electronic still imaging method comprising:

continuously executing imaging of a plurality of times with exposure amounts different from each other;

storing a plurality of original images acquired by the imaging of the plurality of times, respectively; and

detecting positional displacements of common objects included in stored plurality of original images and storing a plurality of corrected original images whose positional displacements are corrected based on detected positional displacements through updating.

20. An electronic still imaging method comprising:

discriminating a luminance range of a picture to be imaged in a plurality of stages;

continuously executing imaging of a plurality of times with exposure amounts different from each other according to a discriminated luminance range;

storing a plurality of original images acquired by the imaging of the plurality of times, respectively; and

outputting an image signal whose dynamic range is expanded by synthesizing the plurality of original images.