IMAGE PICK-UP APPARATUS WITH A SHAKE REDUCING FUNCTION

• US 20090231448A1
• Filed: 05/28/2009
• Published: 09/17/2009
• Est. Priority Date: 06/17/2005
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Sakamoto, Shohei, Tsukagoshi, Takeshi, Matsunaga, Tsuyoshi, Kato, Yoshiyuki, Onozawa, Masaru, YUYAMA, Masami
• Granted Patent: US 8,305,465 B2
• Time in Patent Office: Days
• US Class Current: 348/208.400
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/684 performed by controlling the image sensor readout, e.g. by controlling the integration time
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/76 by influencing the image signals
• CPC Class Codes: H04N 23/815 for controlling the resolution by using a single image
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/46 by combining or binning pixels

Abstract

When a hand shake reducing mode has been set for shooting a subject, an exposure is controlled in accordance with a program diagram (solid line) B for the shake reducing mode, which is different from a program diagram (broken line) A for a normal mode. In a state where a shutter speed is set to less than “ 1/80”, two-pixel addition and/or four-pixel addition is executed on an imaging signal to amplify subject luminance, raising ISO sensitivity. A shutter speed set to fall in a high speed range reduces deterioration in image quality due to hand shake and/or subject movement during a shooting operation.

Claims

1. An image pick-up apparatus comprising:

an image pick-up unit which shoots a subject to output a shot image; and

a driving unit which drives the image pick-up unit in plural fields, and for making the image pick-up unit execute a pixel addition process in a pixel addition mode, whereby pixel signals of plural pixels having the same color and locating adjacent to each other are added in each field.

2. The image pick-up apparatus according to claim 1, wherein

the driving unit makes the image pick-up unit execute the pixel addition process in the pixel addition mode, whereby pixel signals of plural pixels having the same color and locating on plural horizontal lines adjacent to each other are added with a color disposal order kept unchanged in the horizontal direction in each field.

3. The image pick-up apparatus according to claim 2, wherein.

the driving unit makes the image pick-up unit execute the pixel addition process in the pixel addition mode, whereby pixel signals of plural pixels having the same color and locating on odd horizontal lines adjacent to each other and adjacent in the vertical direction are added in an odd field, and pixel signals of plural pixels having the same color and locating on even horizontal lines adjacent to each other and adjacent in the vertical direction are added in an even field.

4. The image pick-up apparatus according to claim 1, wherein the driving unit makes the image pick-up unit execute the pixel addition process in the pixel addition mode, whereby pixel signals of plural pixels having the same color and locating on plural horizontal lines are added with a color disposal order kept unchanged in the horizontal direction and pixel signals of plural pixels having the same color and locating adjacent to each other on the same horizontal line are added in each field.

5. The image pick-up apparatus according to claim 4, wherein the driving unit makes the image pick-up unit execute the pixel addition process in the pixel addition mode, whereby pixel signals of plural pixels having the same color and locating on odd horizontal lines adjacent to each other and adjacent in the vertical direction are added, and pixel signals of plural pixels having the same color and locating adjacent to each other on the same odd horizontal line are added in an odd field, and whereby plural pixels having the same color and locating on even horizontal lines adjacent to each other and adjacent in the vertical direction are added, and pixel signals of plural pixels having the same color and locating adjacent to each other on the same even horizontal line are added in an even field.

6. The image pick-up apparatus according to claim 1, wherein the pixel addition mode comprises plural sorts of pixel addition modes, in which modes the different number of pixels are added respectively, and the driving unit comprises a pixel addition mode switching unit for switching between the plural sorts of pixel addition modes.

7. The image pick-up apparatus according to claim 6, further comprising:

a luminance obtaining unit which obtains a subject luminance, wherein

the pixel addition mode switching unit switches between the plural sorts of pixel addition modes depending on the subject luminance obtained by the luminance obtaining unit.

8. The image pick-up apparatus according to claim 1, wherein

the driving unit comprises a driving mode switching unit which switches between a pixel addition mode and a normal driving mode, wherein in the normal driving mode, the driving unit does not make the image pick-up unit execute the pixel addition process in the pixel addition mode.

9. The image pick-up apparatus according to claim 8, further comprising:

a luminance obtaining unit which obtains a subject luminance, wherein

the driving mode switching unit switches between the pixel addition mode and the normal driving mode, depending on the subject luminance obtained by the luminance obtaining unit.

10. The image pick-up apparatus according to claim 1, further comprising:

an image enlarging unit which performs an enlarging process to enlarge the shot image output from the image pick-up unit, when the pixel addition process has been executed in the image pick-up unit by the driving unit;

a pixel adding count changing unit which changes the number of pixels to be added when the driving unit makes the image pick-up unit execute the pixel addition process; and

an enlarging ratio changing unit which changes an enlarging ratio at which the image enlarging unit executes the enlarging process, when the pixel adding count changing unit has changed the number of pixels to be added.

11. The image pick-up apparatus according to claim 1, further comprising:

a selecting unit which determines whether to make the driving unit execute the pixel addition process or not; and

an image enlarging unit which enlarges the shot image output from the image pick-up unit, after the pixel addition process is executed in the image pick-up unit by the driving unit, when the selecting unit has determined to make the driving unit execute the pixel addition process.

12. The image pick-up apparatus according to claim 1, further comprising:

a phase adjusting unit which adjusts a phase of a color component to be interpolated for each pixel in a color interpolation process on the basis of disposal of pixels included in the shot image in a pixel space, which varies during the pixel addition process executed by the driving unit.

13. An image pick-up apparatus comprising:

an image pick-up unit which shoots a subject to output a shot image;

a pixel adding unit which makes the image pick-up unit execute a pixel addition;

an image enlarging unit which performs an enlarging process to enlarge the shot image output from the image pick-up unit, when the pixel addition process has been executed in the image pick-up unit by the pixel adding unit;

a pixel adding count changing unit which changes the number of pixels to be added in the pixel addition process to be executed by the image pick-up unit; and

an enlarging ratio changing unit which changes the enlarging ratio at which the image enlarging unit executes the enlarging process, when the pixel adding count changing unit has changed the number of pixels to be added.

14. The image pick-up apparatus according to claim 13, wherein

the enlarging ratio changing unit changes the enlarging ratio at which the image enlarging unit executes the enlarging process to an enlarging ratio corresponding to the number of pixels changed by the pixel adding count changing unit.

15. The image pick-up apparatus according to claim 13, further comprising:

an image recording unit which records the shot image which has been subjected to the enlarging process by the image enlarging unit; and

an image size setting unit which sets an image size of the shot image recorded in the image recording unit, wherein

the enlarging ratio changing unit changes the enlarging ratio at which the image enlarging unit executes the enlarging process to an enlarging ratio corresponding to the image size set by the image size setting unit.

16. The image pick-up apparatus according to claim 13, wherein

the enlarging ratio includes an enlarging ratio of not larger than “

1”

(excluding “

0”

).

17. The image pick-up apparatus according to claim 13, wherein

the pixel adding count changing unit comprises a unit for changing the number of pixels to be added to the number of pixels which requires the image pick-up unit not to execute the pixel addition process, and

the image enlarging unit comprises a unit for enlarging the shot image output from the image pick-up unit when the pixel addition process is not executed in the image pick-up unit by the pixel adding unit, when the pixel adding count changing unit has changed the number of pixels to be added to the number of pixels which requires the image pick-up unit not to execute the pixel addition process.

18. The image pick-up apparatus according to claim 13, wherein

the image enlarging unit comprises a unit for enlarging the shot image separately in the vertical and horizontal directions, and

the enlarging ratio changing unit changes the enlarging ratios separately for the vertical and horizontal directions for the image enlarging unit to execute the image enlarging process.

19. The image pick-up apparatus according to claim 13, further comprising:

a luminance obtaining unit which obtains a subject luminance, wherein

the pixel adding count changing unit changes the number of pixels to be added in accordance with the subject luminance obtained by the luminance obtaining unit, when the pixel adding unit makes the image pick-up unit execute the pixel addition process.

20. The image pick-up apparatus according to claim 13, wherein

the pixel adding unit comprises:

a unit which makes the image pick-up unit execute the pixel addition process to add pixel signals of plural pixels having the same color and locating adjacent to each other, and

the image pick-up apparatus, further comprising;

a phase adjusting unit which adjusts a phase of a color component to be interpolated for each pixel in a color interpolation process on the basis of disposal of the pixel included in the shot image in a pixel space, which varies during the pixel addition process executed by the pixel adding unit.

21. An image pick-up apparatus comprising:

an image pick-up unit which shoots a subject to output a shot image;

a pixel adding unit which makes the image pick-up unit execute a pixel addition process;

a selecting unit which determines whether to make the pixel adding unit execute the pixel addition process or not; and

an image enlarging unit which performs an enlarging process to enlarge the shot image output from the image pick-up unit after the pixel addition process is executed in the image pick-up unit by the pixel adding unit, when the selecting unit has determined to make the pixel adding unit execute the pixel addition process.

22. An image pick-up apparatus comprising:

an image pick-up unit which shoots a subject to output a shot image;

a pixel adding unit which makes the image pick-up unit execute a pixel addition process to add pixel signals of plural pixels having the same color and locating adjacent to each other; and

a phase adjusting unit which adjusts a phase of a color component to be interpolated for each pixel in a color interpolation process on the basis of disposal of the pixel included in the shot image in a pixel space, which varies during the pixel addition process executed by the pixel adding unit.

23. The image pick-up apparatus according to claim 22, wherein

the phase adjusting unit converts the shot image output from the image pick-up unit when the pixel addition process has been executed in the image pick-up unit by the pixel adding unit into a reformed image, in which pixels are re-disposed so as to leave an equivalent distance between adjacent pixels in a pixel space with a color disposing order kept unchanged, and each pixel has a pixel value correlated with pixel values of plural pixels having the same color and locating adjacent to such pixel, whereby a phase of a color component to be interpolated for each pixel in the color interpolation process is adjusted.

24. The image pick-up apparatus according to claim 23, wherein

each of pixels included in the shot image output from the image pick-up unit when the pixel addition process has been executed in the image pick-up unit by the pixel adding unit, is converted into a pixel having, as a pixel value, a weighted average of pixel values of pixels having the same color and locating adjacent to such pixel.

25. The image pick-up apparatus according to claim 22, wherein

the phase adjusting unit executes the color interpolation process, and calculates a value of a color component to be interpolated for a target pixel in the color interpolation process, depending on disposal in a pixel space of pixels included in the shot image, whereby a phase of the color component to be interpolated for each pixel is adjusted.

26. The image pick-up apparatus according to claim 25, wherein

the phase adjusting unit uses, as a value of a color component to be interpolated for the target pixel in the color interpolation process, a weighted average of pixel values of plural pixels having the same color as the color component and locating in the vicinity of the target pixel, the weighted average of pixel values of plural pixels being calculated in accordance with distances to the target pixel.

27. The image pick-up apparatus according to claim 22, wherein

the pixel adding unit comprises:

a pixel adding count switching unit which switches between pixel numbers of pixels to be added in the pixel addition process by the pixel adding unit, wherein the phase adjusting unit adjusts a phase of a color component to be interpolated for each pixel in the color interpolation process, depending on disposals in a pixel space of pixels included in the shot image output from the image pick-up unit when the pixel addition process is executed in the image pick-up unit by the pixel adding unit, which disposals are different by the pixel number switched by the pixel adding count switching unit.

28. The image pick-up apparatus according to claim 27, further comprising:

a luminance obtaining unit which obtains a subject luminance, wherein

the pixel adding count switching unit switches between pixel numbers of pixels to be added in the pixel addition process, depending on the subject luminance obtained by the luminance obtaining unit.

29. The image pick-up apparatus according to claim 22, further comprising:

a selecting unit which determines whether to make the pixel adding unit execute the pixel addition process or not, wherein the phase adjusting unit adjusts a phase of a color component to be interpolated for each pixel in the color interpolation process, when the selecting unit has determined to make the pixel adding unit execute the pixel addition process.

30. The image pick-up apparatus according to claim 29, further comprising:

a luminance obtaining unit which obtains a subject luminance, wherein the selecting unit determines whether to make the pixel adding unit execute the pixel addition process or not, depending on the subject luminance obtained by the luminance obtaining unit.