Electronic camera

• US 6,654,062 B1
• Filed: 11/13/1998
• Issued: 11/25/2003
• Est. Priority Date: 11/13/1997
• Status: Expired due to Fees

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Kato, Yoshiyuki, Numata, Hajime
• Primary Examiner(s): Christensen, Andrew
• Assistant Examiner(s): WISDAHL, ERIC D
• Application Number:
  US09/191,909
• Time in Patent Office: 1,838 Days
• Field of Search: 348/362, 348/364, 348/218.1, 348/221.1, 348/370, 348/371, 396/157, 396/159, 396/161, 396/164
• US Class Current: 348/362
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 23/75 by influencing optical camera components

Abstract

An electronic camera comprises a flash unit. When the electric camera takes a picture using the flash unit, the electronic camera determines a first optimum flash exposure for a central area of the object to be taken and a second optimum flash exposure for a background area of the object to be taken. Further, the camera produces first image data corresponding to a picture taken under the first optimum flash exposure and second image data corresponding to a picture taken under the second optimum flash exposure. The central area of the first image data is cut out from the first image data and written over the second image data.

Claims

1. An electronic camera for recording an image, comprising:

image sensing means for optically capturing such an image and providing electric signals representative of the captured image;

a flash unit for emitting flash light;

image discriminating means for discriminating between a first area and a second area in an image to be recorded based upon the electric signals provided by the image sensing means;

first exposure control means for determining a first flash exposure for the first area discriminated by the image discriminating means;

first exposure means including first flash exposure means for activating the flash unit and exposing the image to the image sensing means according to the first flash exposure determined by the first exposure control means;

first image data producing means for producing first image data based upon the electric signals provided by the image sensing means in response to the first flash exposure;

second exposure control means for determining a second exposure for the second area discriminated by the image discriminating means based upon the electric signals provided by the image sensing means in response to the first flash exposure;

second exposure means for exposing the image to the image sensing means according to the second exposure determined by the second exposure control means;

second image data producing means for producing second image data based upon the electric signals provided by the image sensing means in response to the second exposure; and

combining means for combining at least part of the first image data produced by the first image data producing means and at least part of the second image data produced by the second image data producing means into an overall resultant image.

2. An electronic camera for recording an image as set forth in claim 1, wherein the second exposure control means determines a second flash exposure for the second area discriminated by the image discriminating means based upon the electric signals representative of the second area, which are provided by the image sensing means in response to the first flash exposure, and the second exposure means includes second flash exposure means for activating the flash unit and exposing the image to the image sensing means according to the second flash exposure determined by the second exposure control means.

3. An electronic camera for recording an image as set forth in claim 2, further comprising:

means for acquiring data regarding the brightness of the image in the second area as a result of the first flash exposure;

wherein the second exposure control means determines the second flash exposure for the second area based upon the brightness in the second area.

4. An electronic camera for recording an image as set forth in claim 1, further comprising:

means for acquiring data regarding the brightness of the image in the second area both prior to the first flash exposure and as a result of the first flash exposure;

wherein the second exposure control means determines a second flash exposure for the second area based upon the brightness data and the second exposure means includes second flash exposure means for activating the flash unit and exposing the image to the image sensing means according to the second flash exposure determined by the second exposure control means.

5. An electronic camera for recording an image as set forth in claim 4, wherein the second exposure control means determines a second flash exposure for the second area based at least in part upon the difference in the brightness of the second area prior to the first flash exposure and as a result of the first flash exposure.

6. An electronic camera for recording an image as set forth in claim 1, wherein the combining means includes means for extracting image data for the first area of the first image data produced by the first image data producing means, and means for combining the image data so extracted with at least part of the second image data produced by the second image data producing means.

7. An electronic camera for recording an image as set forth in claim 1, further comprising:

means for acquiring data regarding the brightness of the image in the first and second areas prior to the first flash exposure;

comparing means for comparing the brightness of the first area relative to that of the second area; and

means for inhibiting the operation of the second exposure control means, the second exposure means and the second image data producing means based upon the result of the comparison made by the comparing means.

8. An electronic camera for recording an image as set forth in claim 1, further comprising:

first distance measuring means for measuring the distance between an object in the first area discriminated by the image discriminating means and the flash unit;

second distance measuring means for measuring the distance between an object in the second area discriminated by the image discriminating means and the flash unit;

comparing means for comparing the distances measured by the first and second distance measuring means; and

means for inhibiting the operation of the second exposure control means, the second exposure means and the second image data producing means based upon the result of the comparison made by the comparing means.

9. An electronic camera for recording an image as set forth in claim 1, further comprising:

amplifier means for amplifying the electric signals provided by the image sensing means by an adjustable gain;

wherein the first exposure means includes means for adjusting the gain of the amplifier means corresponding to the first flash exposure determined by the first exposure control means, and the second exposure means includes means for adjusting the gain of the amplifier means corresponding to the second exposure determined by the second exposure control means.

10. A method of operating an electronic camera which has image sensing means for optically capturing an image and providing electric signals representative of the captured image and a flash unit for emitting flash light, the method comprising:

an image discriminating step for discriminating between a first area and a second area in an image to be recorded based upon the electric signals provided by the image sensing means;

a first exposure control step for determining a first flash exposure for the first area discriminated by the image discriminating step;

a first exposure step including a first flash exposure step for activating the flash unit and exposing the image to the image sensing means according to the first flash exposure determined by the first exposure control step;

a first image data producing step for producing first image data based upon the electric signals provided by the image sensing means in response to the first flash exposure;

a second exposure control step for determining a second exposure for the second area discriminated by the image discriminating step based upon the electric signals provided by the image sensing means in response to the first flash exposure;

a second exposure step for exposing the image to the image sensing means according to the second exposure determined by the second exposure control step;

a second image data producing step for producing second image data based upon the electric signals provided by the image sensing means in response to the second exposure; and

a combining step for combining at least part of the first image data produced by the first image data producing step and at least part of the second image data produced by the second image data producing step into an overall resultant image.

11. A method of operating an electronic camera as set forth in claim 10, wherein the second exposure control step determines a second flash exposure for the second area discriminated by the image discriminating step based upon the electric signals representative of the second area, which are provided by the image sensing means in response to the first flash exposure, and the second exposure step includes a second flash exposure step for activating the flash unit and exposing the image to the image sensing means according to the second flash exposure determined by the second exposure control step.

12. A method of operating an electronic camera as set forth in claim 11, further comprising:

a step for acquiring data regarding the brightness of the image in the second area as a result of the first flash exposure;

wherein the second exposure control step determines the second flash exposure for the second area based upon the brightness in the second area.

13. A method of operating an electronic camera as set forth in claim 10, further comprising:

a step for acquiring data regarding the brightness of the image in the second area both prior to the first flash exposure and as a result of the first flash exposure;

wherein the second exposure control step determines a second flash exposure for the second area based upon the brightness data and the second exposure step includes a second flash exposure step for activating the flash unit and exposing the image to the image sensing means according to the second flash exposure determined by a second exposure control step.

14. A method of operating an electronic camera as set forth in claim 13, wherein the second exposure control step determines the second flash exposure for the second area based at least in part upon the difference in the brightness of the second area prior to the first flash exposure and as a result of the first flash exposure.

15. A method of operating an electronic camera as set forth in claim 10, wherein the combining step includes a step for extracting image data for the first area of the first image data produced by the first image data producing step, and a step for combining the image data so extracted with at least part of the second image data produced by the second image data producing step.

16. A method of operating an electronic camera as set forth in claim 10, further comprising:

a step for acquiring data regarding the brightness of the image in the first and second areas prior to the first flash exposure;

a comparing step for comparing the brightness of the first area relative to that of the second area; and

a step for inhibiting the process of the second exposure control step, the second exposure step and the second image data producing step based upon the result of the comparison made by the comparing step.

17. A method of operating an electronic camera as set forth in claim 10, further comprising:

a first distance measuring step for measuring the distance between an object in the first area discriminated by the image discriminating step and the flash unit;

a second distance measuring step for measuring the distance between an object in the second area discriminated by the image discriminating step and the flash unit;

a comparing step for comparing the distances measured by the first and second distance measuring steps; and

a step for inhibiting the operation of the second exposure control step, the second exposure step and the second image data producing step based upon the result of the comparison made by the comparing step.

18. An electronic camera for recording an image, comprising:

image sensing means for optically capturing such an image and providing electric signals representative of the captured image;

a flash unit for emitting flash light;

image discriminating means for discriminating between a first area and a second area in an image to be recorded based upon the electric signals provided by the image sensing means;

first exposure control means for determining a first flash exposure for the first area discriminated by the image discriminating means;

first exposure means including first flash exposure means for activating the flash unit and exposing the image to the image sensing means according to the first flash exposure determined by the first exposure control means;

first image data producing means for producing first image data based upon the electric signals provided by the image sensing means in response to the first flash exposure;

means for acquiring data regarding the brightness of the image in the second area both prior to the first flash exposure and as a result of the first flash exposure;

second exposure control means for determining a second flash exposure for the second area discriminated by the image discriminating means based at least in part upon the difference in the brightness of the second area prior to the first flash exposure and as a result of the first flash exposure;

second exposure means including second flash exposure means for activating the flash unit and exposing the image to the image sensing means according to the second flash exposure determined by the second exposure control means; and

second image data producing means for producing second image data based upon the electric signals provided by the image sensing means in response to the second exposure.

19. An electronic camera for recording an image, comprising:

image sensing means for optically capturing such an image and providing electric signals representative of the captured image;

a flash unit for emitting flash light;

image discriminating means for discriminating between a first area and a second area in an image to be recorded based upon the electric signals provided by the image sensing means;

first exposure control means for determining a first flash exposure for the first area discriminated by the image discriminating means;

first exposure means including first flash exposure means for activating the flash unit and exposing the image to the image sensing means according to the first flash exposure determined by the first exposure control means;

first image data producing means for producing first image data based upon the electric signals provided by the image sensing means in response to the first flash exposure;

second exposure control means for determining a second exposure for the second area discriminated by the image discriminating means based upon the electric signals provided by the image sensing means in response to the first flash exposure;

second exposure means for exposing the image to the image sensing means according to the second exposure determined by the second exposure control means;

second image data producing means for producing second image data based upon the electric signals provided by the image sensing means in response to the second exposure;

means for acquiring data regarding the brightness of the image in the first and second areas prior to the first flash exposure;

comparing means for comparing the brightness of the first area relative to that of the second area; and

means for inhibiting the operation of the second exposure control means, the second exposure means and the second image data producing means based upon the result of the comparison made by the comparing means.

20. An electronic camera for recording an image, comprising:

image sensing means for optically capturing such an image and providing electric signals representative of the captured image;

a flash unit for emitting flash light;

image discriminating means for discriminating between a first area and a second area in an image to be recorded based upon the electric signals provided by the image sensing means;

first exposure control means for determining a first flash exposure for the first area discriminated by the image discriminating means;

first exposure means including first flash exposure means for activating the flash unit and exposing the image to the image sensing means according to the first flash exposure determined by the first exposure control means;

first image data producing means for producing first image data based upon the electric signals provided by the image sensing means in response to the first flash exposure;

second exposure control means for determining a second exposure for the second area discriminated by the image discriminating means based upon the electric signals provided by the image sensing means in response to the first flash exposure;

second exposure means for exposing the image to the image sensing means according to the second exposure determined by the second exposure control means;

second image data producing means for producing second image data based upon the electric signals provided by the image sensing means in response to the second exposure;

first distance measuring means for measuring the distance between an object in the first area discriminated by the image discriminating means and the flash unit;

second distance measuring means for measuring the distance between an object in the second area discriminated by the image discriminating means and the flash unit;

comparing means for comparing the distances measured by the first and second distance measuring means; and

means for inhibiting the operation of the second exposure control means, the second exposure means and the second image data producing means based upon the result of the comparison made by the comparing means.

21. A method of operating an electronic camera which has image sensing means for optically capturing an image and providing electric signals representative of the captured image and a flash unit for emitting flash light, the method comprising:

an image discriminating step for discriminating between a first area and a second area in an image to be recorded based upon the electric signals provided by the image sensing means;

a first exposure control step for determining a first flash exposure for the first area discriminated by the image discriminating step;

a first exposure step including a first flash exposure step for activating the flash unit and exposing the image to the image sensing means according to the first flash exposure determined by the first exposure control step;

a first image data producing step for producing first image data based upon the electric signals provided by the image sensing means in response to the first flash exposure;

a step for acquiring data regarding the brightness of the image in the second area both prior to the first flash exposure and as a result of the first flash exposure;

a second exposure control step for determining a second flash exposure for the second area discriminated by the image discriminating step based at least in part upon the difference in the brightness of the second area prior to the first flash exposure and as a result of the first flash exposure;

a second exposure step including a second flash exposure step for activating the flash unit and exposing the image to the image sensing means according to the second flash exposure determined by the second exposure control step; and

a second image data producing step for producing second image data based upon the electric signals provided by the image sensing means in response to the second exposure.

22. A method of operating an electronic camera which has image sensing means for optically capturing an image and providing electric signals representative of the captured image and a flash unit for emitting flash light, the method comprising:

an image discriminating step for discriminating between a first area and a second area in an image to be recorded based upon the electric signals provided by the image sensing means;

a first exposure control step for determining a first flash exposure for the first area discriminated by the image discriminating step;

a first exposure step including a first flash exposure step for activating the flash unit and exposing the image to the image sensing means according to the first flash exposure determined by the first exposure control step;

a first image data producing step for producing first image data based upon the electric signals provided by the image sensing means in response to the first flash exposure;

a second exposure control step for determining a second exposure for the second area discriminated by the image discriminating step based upon the electric signals provided by the image sensing means in response to the first flash exposure;

a second exposure step for exposing the image to the image sensing means according to the second exposure determined by the second exposure control step;

a second image data producing step for producing second image data based upon the electric signals provided by the image sensing means in response to the second exposure;

a step for acquiring data regarding the brightness of the image in the first and second areas prior to the first flash exposure;

a comparing step for comparing the brightness of the first area relative to that of the second area; and

a step for inhibiting the process of the second exposure control step, the second exposure step and the second image data producing step based upon the result of the comparison made by the comparing step.

23. A method of operating an electronic camera which has image sensing means for optically capturing an image and providing electric signals representative of the captured image and a flash unit for emitting flash light, the method comprising:

an image discriminating step for discriminating between a first area and a second area in an image to be recorded based upon the electric signals provided by the image sensing means;

a first exposure control step for determining a first flash exposure for the first area discriminated by the image discriminating step;

a first exposure step including a first flash exposure step for activating the flash unit and exposing the image to the image sensing means according to the first flash exposure determined by the first exposure control step;

a first image data producing step for producing first image data based upon the electric signals provided by the image sensing means in response to the first flash exposure;

a second exposure control step for determining a second exposure for the second area discriminated by the image discriminating step based upon the electric signals provided by the image sensing means in response to the first flash exposure;

a second exposure step for exposing the image to the image sensing means according to the second exposure determined by the second exposure control step;

a second image data producing step for producing second image data based upon the electric signals provided by the image sensing means in response to the second exposure;

a first distance measuring step for measuring the distance between an object in the first area discriminated by the image discriminating step and the flash unit;

a second distance measuring step for measuring the distance between an object in the second area discriminated by the image discriminating step and the flash unit;

a comparing step for comparing the distances measured by the first and second distance measuring steps; and

a step for inhibiting the operation of the second exposure control step, the second exposure step and the second image data producing step based upon the result of the comparison made by the comparing step.