Image sensing apparatus

• US 20050162532A1
• Filed: 01/21/2005
• Published: 07/28/2005
• Est. Priority Date: 01/26/2004
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Toyoda, Tetsuya
• Granted Patent: US 7,580,061 B2
• Time in Patent Office: Days
• US Class Current: 348/231.600
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

An image sensing apparatus according to one mode of the present invention enhances precision of WB adjustment to thereby obtain an image having an appropriate WB, and comprises an image signal processing circuit which adjusts the WB with respect to an image signal output from an image sensing element based on a WB gain, a ROM which stores at least a WB correction coefficient correspondence table, and a WB modification coefficient correspondence table, and a microcomputer which calculates a WB correction coefficient corresponding to a diaphragm value, and a WB modification coefficient based on the correspondence tables and which multiplies the WB gain by the WB correction coefficient and WB modification coefficient to thereby obtain a value as a digital gain and which executes a control in such a manner as to adjust the WB based on the digital gain.

Claims

1. An image sensing apparatus comprising:

image sensing section which has an image sensing element which picks up a subject image passed through a photographing lens having a diaphragm regulating a quantity of light to thereby output an image signal;

storage section which stores a white balance modification coefficient further modifying a white balance correction coefficient in accordance with an optical characteristic of the image sensing section, the white balance correction coefficient performing white balance correction with respect to the image signal output from the image sensing section in accordance with an incidence characteristic upon the image sensing section based on optical characteristics including setting of the diaphragm of the photographing lens; and

adjustment control section which performs white balance adjustment with respect to the image signal output from the image sensing section based on the white balance correction coefficient modified by the white balance modification coefficient.

2. The image sensing apparatus according to claim 1, wherein the photographing lens is detachably attached to the image sensing apparatus, and the white balance correction coefficient is stored in the photographing lens.

3. An image sensing apparatus comprising:

image sensing section which picks up a subject image passed through an optical system to thereby output an image signal;

image signal processing section which adjusts a white balance with respect to the image signal output from the image sensing section; and

control section which reads a white balance correction coefficient which performs correction corresponding to a characteristic of a diaphragm of the optical system, and a white balance modification coefficient which further modifies the white balance correction coefficient and which performs correction corresponding to an optical characteristic of the image sensing section, calculating a digital gain which amplifies a signal for each color included in the image signal output from the image sensing section based on the white balance correction coefficient and the white balance modification coefficient, and executing a control by the digital gain in such a manner as to adjust the white balance by the image signal processing section.

4. The image sensing apparatus according to claim 3, wherein at least the image sensing section is detachably attached to the image sensing apparatus, and the white balance modification coefficient is stored in the image sensing section.

5. The image sensing apparatus according to claim 3, wherein the white balance correction coefficient includes at least a correction coefficient corresponding to a light receiving characteristic of a light receiving position outside an optical axis of a light receiving section picked up by the image sensing section, and the white balance modification coefficient has a coefficient which modifies a value of the white balance correction coefficient.

6. An image sensing apparatus capable of performing prior photographing to pick up an image of a subject which constitutes a white reference beforehand and accordingly calculate a gain for white balance adjustment prior to actual photographing, the apparatus comprising:

image sensing section which picks up a subject image passed through an optical system to thereby output an image signal;

image signal processing section which adjusts a white balance with respect to the image signal output from the image sensing section; and

control section which reads a first white balance correction coefficient performing correction corresponding to a characteristic relating to a diaphragm of the optical system and corresponding to a diaphragm value at a prior photographing time at an actual photographing time, reading a second white balance correction coefficient further performing correction corresponding to the characteristic relating to the diaphragm of the optical system and corresponding to a diaphragm value at the actual photographing time, and a white balance modification coefficient further modifying the first and second white balance correction coefficients and performing correction corresponding to an optical characteristic of the image sensing section, calculating a digital gain amplifying a signal for each color included in the image signal output from the image sensing section by the white balance modification coefficient, and adjusting the white balance by the image signal processing means based on the digital gain.

7. An image sensing apparatus comprising:

image sensing section which picks up a subject image passed through an optical system to thereby output an image signal;

image signal processing section which adjusts a white balance based on the image signal output from the image sensing section;

storage section which stores at least a first table in which a diaphragm value is associated with a white balance correction coefficient performing correction corresponding to a characteristic relating to a diaphragm of the optical system, and a second table in which the white balance correction coefficient is associated with a white balance modification coefficient further modifying the white balance correction coefficient and performing correction corresponding to an optical characteristic of the image sensing section; and

control section which calculates the white balance correction coefficient corresponding to a diaphragm value, and the white balance modification coefficient based on the first and second tables, multiplying the white balance gain by the white balance correction coefficient and the white balance modification coefficient to thereby obtain a value as a digital gain amplifying a signal for each color included in the image signal output from the image sensing section, and executing a control based on the digital gain to thereby adjust the white balance by the image signal processing section.

8. The image sensing apparatus according to claim 7, wherein the second table is determined beforehand based on the optical characteristic of an image sensing element.

9. An image sensing apparatus comprising:

image sensing section which picks up a subject image passed through an optical system to thereby output an image signal;

image signal processing section which adjusts a white balance based on the image signal output from the image sensing section;

storage section which stores at least a first table in which a diaphragm value is associated with a white balance correction coefficient performing correction corresponding to a characteristic relating to a diaphragm of the optical system, and a second table in which the white balance correction coefficient is associated with a white balance modification coefficient further modifying the white balance correction coefficient and performing correction corresponding to an optical characteristic of the image sensing section; and

control section which calculates a first white balance correction coefficient corresponding to a diaphragm value at a prior photographing time based on the first table, reading a second white balance correction coefficient corresponding to a diaphragm value at an actual photographing time, and a white balance modification coefficient based on the first and second tables, multiplying a white balance gain by a value obtained by dividing the second white balance correction coefficient by the first white balance correction coefficient, and the white balance modification coefficient to thereby obtain a value as a digital gain amplifying a signal for each color included in the image signal output from the image sensing section, and executing a control based on the digital gain to thereby adjust the white balance by the image signal processing means at the actual photographing time.

10. The image sensing apparatus according to claim 9, wherein the second table is determined beforehand based on an optical characteristic of an image sensing element.

11. An image sensing apparatus comprising:

image sensing section which picks up a subject image passed through an optical system to thereby output an image signal;

image signal processing section which adjusts a white balance with respect to the image signal output from the image sensing section based on a white balance gain;

storage section which stores at least a first table in which a diaphragm value is associated with a white balance correction coefficient performing correction corresponding to a characteristic relating to a diaphragm of the optical system, and a second table in which the white balance correction coefficient is associated with a white balance modification coefficient further modifying the white balance correction coefficient and performing correction corresponding to an optical characteristic of the image sensing section;

switching section which switches a photographing mode; and

control section which reads the white balance correction coefficient corresponding to the diaphragm value, and the white balance modification coefficient based on the first and second tables, multiplying the white balance gain by the white balance correction coefficient and the white balance modification coefficient to thereby obtain a value as a digital gain amplifying a signal for each color included in the image signal output from the image sensing section, and executing a control based on the digital gain in such a manner as to adjust the white balance by the image signal processing section in a first photographing mode, and

reading a first white balance correction coefficient corresponding to a diaphragm value at a prior photographing time based on the first table, reading a second white balance correction coefficient corresponding to a diaphragm value at an actual photographing time, and the white balance modification coefficient based on the first and second tables, multiplying the white balance gain by a value obtained by dividing the second white balance correction coefficient by the first white balance correction coefficient, and the white balance modification coefficient to thereby obtain a value as a digital gain amplifying a signal for each color included in the image signal output from the image sensing section, and executing a control based on the digital gain to thereby adjust the white balance by the image signal processing section in a second photographing mode.

12. The image sensing apparatus according to claim 11, wherein the second table is determined beforehand based on an optical characteristic of an image sensing element.

13. An image sensing apparatus which picks up a subject image obtained by a replaceable photographing lens by image sensing section to thereby obtain image data, the apparatus comprising:

correction coefficient storage section which stores a correction coefficient performing correction corresponding to an optical characteristic relating to the photographing lens;

modification coefficient storage section which stores a modification coefficient modifying the correction coefficient in accordance with an optical characteristic relating to the image sensing section; and

white balance adjustment section which adjusts a white balance of the image data obtained by the image sensing based on the correction coefficient and the modification coefficient corresponding to the applied photographing lens.

14. The image sensing apparatus according to claim 13, wherein the correction coefficient storage section is disposed in the photographing lens, the image sensing apparatus further comprising:

communication section which receives the correction coefficient transmitted from the photographing lens.

15. The image sensing apparatus according to claim 13, wherein the modification coefficient storage section is disposed in an apparatus in which the image sensing section is disposed.

16. An image sensing apparatus comprising:

image sensing section which picks up a subject image passed through a replaceable photographing lens by an image sensing element to thereby output an image signal;

image signal processing section which adjusts a white balance with respect to the image signal output from the image sensing section;

storage section which stores a white balance correction coefficient corresponding to an optical characteristic of the attached replaceable lens, and a white balance modification coefficient corresponding to an optical characteristic of the image sensing section; and

control section which executes a control in such a manner as to adjust the white balance based on the white balance correction coefficient and the white balance modification coefficient.

17. The image sensing apparatus according to claim 16, wherein the white balance correction coefficient corresponding to the optical characteristic of the replaceable lens, and the white balance modification coefficient corresponding to the optical characteristic of the image sensing section are coefficients with respect to the image sensing element having an optical characteristic which is a reference.

18. An image sensing apparatus comprising:

image sensing means having an image sensing element which picks up a subject image passed through a photographing lens having a diaphragm regulating a quantity of light to thereby output an image signal;

storage means for storing a white balance modification coefficient further modifying a white balance correction coefficient in accordance with an optical characteristic of the image sensing means, the white balance correction coefficient performing white balance correction with respect to the image signal output from the image sensing means in accordance with an incidence characteristic upon the image sensing means based on optical characteristics including setting of the diaphragm of the photographing lens; and

adjustment control means for performing white balance adjustment with respect to the image signal output from the image sensing means based on the white balance correction coefficient modified by the white balance modification coefficient.

19. An image sensing apparatus comprising:

image sensing means for picking up a subject image passed through an optical system to thereby output an image signal;

image signal processing means for adjusting a white balance with respect to the image signal output from the image sensing means; and

control means for reading a white balance correction coefficient which performs correction corresponding to a characteristic of a diaphragm of the optical system, and a white balance modification coefficient which further modifies the white balance correction coefficient and which performs correction corresponding to an optical characteristic of the image sensing means, calculating a digital gain which amplifies a signal for each color included in the image signal output from the image sensing means based on the white balance correction coefficient and the white balance modification coefficient, and executing a control by the digital gain in such a manner as to adjust the white balance by the image signal processing means.

20. An image sensing apparatus capable of performing prior photographing to pick up an image of a subject which constitutes a white reference beforehand and accordingly calculate a gain for white balance adjustment prior to actual photographing, the apparatus comprising:

image sensing means for picking up a subject image passed through an optical system to thereby output an image signal;

image signal processing means for adjusting a white balance with respect to the image signal output from the image sensing means; and

control means for reading a first white balance correction coefficient performing correction corresponding to a characteristic relating to a diaphragm of the optical system and corresponding to a diaphragm value at a prior photographing time at an actual photographing time, reading a second white balance correction coefficient further performing correction corresponding to the characteristic relating to the diaphragm of the optical system and corresponding to a diaphragm value at the actual photographing time, and a white balance modification coefficient further modifying the first and second white balance correction coefficients and performing correction corresponding to an optical characteristic of the image sensing means, calculating a digital gain amplifying a signal for each color included in the image signal output from the image sensing means by the white balance modification coefficient, and adjusting the white balance by the image signal processing means based on the digital gain.

21. An image sensing apparatus comprising:

image sensing means for picking up a subject image passed through an optical system to thereby output an image signal;

image signal processing means for adjusting a white balance based on the image signal output from the image sensing means;

storage means for storing at least a first table in which a diaphragm value is associated with a white balance correction coefficient performing correction corresponding to a characteristic relating to a diaphragm of the optical system, and a second table in which the white balance correction coefficient is associated with a white balance modification coefficient further modifying the white balance correction coefficient and performing correction corresponding to an optical characteristic of the image sensing means; and

control means for calculating the white balance correction coefficient corresponding to a diaphragm value, and the white balance modification coefficient based on the first and second tables, multiplying the white balance gain by the white balance correction coefficient and the white balance modification coefficient to thereby obtain a value as a digital gain amplifying a signal for each color included in the image signal output from the image sensing means, and executing a control based on the digital gain to thereby adjust the white balance by the image signal processing means.

22. An image sensing apparatus comprising:

image sensing means for picking up a subject image passed through an optical system to thereby output an image signal;

image signal processing means for adjusting a white balance based on the image signal output from the image sensing means;

storage means for storing at least a first table in which a diaphragm value is associated with a white balance correction coefficient performing correction corresponding to a characteristic relating to a diaphragm of the optical system, and a second table in which the white balance correction coefficient is associated with a white balance modification coefficient further modifying the white balance correction coefficient and performing correction corresponding to an optical characteristic of the image sensing means; and

control means for calculating a first white balance correction coefficient corresponding to a diaphragm value at a prior photographing time based on the first table, reading a second white balance correction coefficient corresponding to a diaphragm value at an actual photographing time, and a white balance modification coefficient based on the first and second tables, multiplying a white balance gain by a value obtained by dividing the second white balance correction coefficient by the first white balance correction coefficient, and the white balance modification coefficient to thereby obtain a value as a digital gain amplifying a signal for each color included in the image signal output from the image sensing means, and executing a control based on the digital gain to thereby adjust the white balance by the image signal processing means at the actual photographing time.

23. An image sensing apparatus comprising:

image sensing means for picking up a subject image passed through an optical system to thereby output an image signal;

image signal processing means for adjusting a white balance with respect to the image signal output from the image sensing means based on a white balance gain;

storage means for storing at least a first table in which a diaphragm value is associated with a white balance correction coefficient performing correction corresponding to a characteristic relating to a diaphragm of the optical system, and a second table in which the white balance correction coefficient is associated with a white balance modification coefficient further modifying the white balance correction coefficient and performing correction corresponding to an optical characteristic of the image sensing means;

switching means for switching a photographing mode; and

control means for reading the white balance correction coefficient corresponding to the diaphragm value, and the white balance modification coefficient based on the first and second tables, multiplying the white balance gain by the white balance correction coefficient and the white balance modification coefficient to thereby obtain a value as a digital gain amplifying a signal for each color included in the image signal output from the image sensing means, and executing a control based on the digital gain in such a manner as to adjust the white balance by the image signal processing means in a first photographing mode, and

reading a first white balance correction coefficient corresponding to a diaphragm value at a prior photographing time based on the first table, reading a second white balance correction coefficient corresponding to a diaphragm value at an actual photographing time, and the white balance modification coefficient based on the first and second tables, multiplying the white balance gain by a value obtained by dividing the second white balance correction coefficient by the first white balance correction coefficient, and the white balance modification coefficient to thereby obtain a value as a digital gain amplifying a signal for each color included in the image signal output from the image sensing means, and executing a control based on the digital gain to thereby adjust the white balance by the image signal processing means in a second photographing mode.

24. An image sensing apparatus which picks up a subject image obtained by a replaceable photographing lens by image sensing means to thereby obtain image data, the apparatus comprising:

correction coefficient storage means for storing a correction coefficient performing correction corresponding to an optical characteristic relating to the photographing lens;

modification coefficient storage means for storing a modification coefficient modifying the correction coefficient in accordance with an optical characteristic relating to the image sensing means; and

white balance adjustment means for adjusting a white balance of the image data obtained by the image sensing based on the correction coefficient and the modification coefficient corresponding to the applied photographing lens.

25. An image sensing apparatus comprising:

image sensing means for picking up a subject image passed through a replaceable photographing lens by an image sensing element to thereby output an image signal;

image signal processing means for adjusting a white balance with respect to the image signal output from the image sensing means;

storage means for storing a white balance correction coefficient corresponding to an optical characteristic of the attached replaceable lens, and a white balance modification coefficient corresponding to an optical characteristic of the image sensing means; and

control means for executing a control in such a manner as to adjust the white balance based on the white balance correction coefficient and the white balance modification coefficient.