IMAGE SENSING APPARATUS AND METHOD FOR CONTROLLING THE SAME

• US 20100026835A1
• Filed: 04/20/2007
• Published: 02/04/2010
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Suwa, Takeshi, Negishi, Norio
• Granted Patent: US 8,314,850 B2
• Time in Patent Office: Days
• US Class Current: 348/223.100
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control
• CPC Class Codes: H04N 25/42 by switching between different modes of operation using different resolutions or aspect ratios, e.g. switching between interlaced and non-interlaced mode
• CPC Class Codes: H04N 25/443 by reading pixels from selected 2D regions of the array, e.g. for windowing or digital zooming
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 3/1562 for selective scanning, e.g. windowing, zooming
• CPC Class Codes: H04N 9/643 Hue control means, e.g. flesh tone control

Abstract

Using correction values obtained based on image signals outputted from an image sensing unit by controlling the image sensing unit in the first mode, in which image signals are read out from a first photoelectric conversion element group arranged in a first region of an image sensing plane, the image signals outputted from an image sensing apparatus by controlling the image sensing unit in the second mode, in which image signals are read out from a second photoelectric conversion element group arranged in a second region that is smaller than the first region of the image sensing plane, are subjected to a white balance process.

Claims

1. An image sensing apparatus comprising:

an image sensing unit in which a plurality of photoelectric conversion elements are arranged on a image sensing plane; and

a control unit, wherein

said control unit has a first mode in which image signals are read out from a first photoelectric conversion element group arranged in a first region of said image sensing plane; and

a second mode in which image signals are read out from a second photoelectric conversion element group arranged in a second region that is smaller than said first region of said image sensing plane, and

using correction values obtained based on said image signals outputted from said image sensing unit by controlling said image sensing unit in said first mode, said image signals outputted from said image sensing unit by controlling said image sensing unit in said second mode are subjected to a white balance process.

2. The image sensing apparatus according to claim 1, wherein

said control unit controls said image sensing unit in said second mode based on a set electronic zoom magnification so as to generate an image based on said second photoelectric conversion element group arranged in said second region.

3. The image sensing apparatus according to claim 2, wherein

when said electronic zoom magnification is set and said image signals are read out at a rate of m frames (m being an integer equal to or greater than 2) per a predetermined second, said control unit reads out n frames (n being an integer equal to or greater than 1 and smaller than m) of said m frames in said first mode, and reads out m−

n frames of said m frames in said second mode.

4. The image sensing apparatus according to claim 3, wherein

said control unit performs the readout in said first mode at a predetermined frame interval.

5. The image sensing apparatus according to claim 4, wherein

said image sensing unit further comprises an adding unit configured to add some of said signals read out from said first photoelectric conversion group in said first mode.

6. The image sensing apparatus according to claim 5, wherein

said control unit sets the number of signals to be added by said adding unit such that the frame rates of said first mode and said second mode are the same.

7. The image sensing apparatus according to claim 4, wherein

said control unit reads out said first photoelectric conversion group by thinning in said first mode.

8. The image sensing apparatus according to claim 7, wherein

said control unit sets a thinning rate for said thinning readout such that the frame rates of said first mode and said second mode are the same.

9. The image sensing apparatus according to claim 1, wherein

said control unit generates an image based on a photoelectric conversion element group, which is arranged in a region smaller than said first region, of said image signals read out in said first mode.

10. The image sensing apparatus according to claim 9, further comprising an adjustment unit that performs control so as to reduce a resolution difference between said image based on said image signals read out in said second mode and an image based on a photoelectric conversion element group, which is arranged in a region smaller than said first region, of said image signals read out in said first mode.

11. An image sensing apparatus comprising:

an image sensing unit in which a plurality of photoelectric conversion elements are arranged on a image sensing plane; and

a control unit, wherein

said control unit has a first mode in which image signals are read out from a first photoelectric conversion element group arranged in a first region of said image sensing plane, the image signals being read out individually for each of a plurality of divided regions into which said first region is divided; and

a second mode in which image signals are read out from a second photoelectric conversion element group arranged in a second region that is smaller than said first region of said image sensing plane,

the readout of said signal images of said divided regions is performed in said first mode between the readout of image signals in said second mode and the subsequent readout of image signals in said second mode,

correction values are calculated based on at least said image signals of said divided regions read out in said first mode, and

said image signals read out in said second mode are subjected to a white balance process.

12. The image sensing apparatus according to claim 11, wherein

said control unit controls such that the readout in said first mode and the readout in said second mode are performed alternately.

13. The image sensing apparatus according to claim 11, wherein

said control unit controls such that the readout in said first mode is performed once every M times (M being an integer equal to or greater than 2) of the readout in said second mode.

14. The image sensing apparatus according to claim 11, wherein

said control unit changes said divided regions read out in said first mode every time the readout in said first mode is performed.

15. The image sensing apparatus according to claim 14, wherein

said control unit calculates said correction values when the total size of said divided regions read out in said first mode exceeds the size of said second region.

16. The image sensing apparatus according to claim 15, wherein

said control unit calculates said correction values when the total size of said divided regions read out in said first mode equals the size of said first region.

17. The image sensing apparatus according to claim 14, wherein

said control unit calculates said correction values every time the readout from said divided regions is performed in said first mode.

18. The image sensing apparatus according to claim 11, wherein

said control unit divides a region excluding said second region on said image sensing plane into said divided regions.

19. The image sensing apparatus according to claim 11, further comprising a readout means for reading out image signals from said photoelectric conversion elements.

20. The image sensing apparatus according to claim 14, wherein

said readout means reads out image signals from a first photoelectric conversion element group arranged in all of said divided regions within a predetermined number of frames.

21. A method for controlling an image sensing apparatus having a first mode in which image signals are read out from a first photoelectric conversion element group arranged in a first region of a image sensing plane;

and a second mode in which image signals are read out from a second photoelectric conversion element group arranged in a second region that is smaller than said first region of said image sensing plane,

said method comprising steps of;

performing a white balance process of said image signals outputted from an image sensing unit by controlling said image sensing unit in said second mode using correction values obtained based on said image signals outputted from said image sensing unit by controlling said image sensing unit in said first mode, and

generating an image based on said second photoelectric conversion element group arranged in said second region.

22. A method for controlling an image sensing apparatus comprises an image sensing unit in which a plurality of photoelectric conversion elements are arranged on a image sensing plane, and a control unit that controls said image sensing unit, wherein said control unit has a first mode in which image signals are read out from a first photoelectric conversion element group arranged in a first region of said image sensing plane, the image signals being read out individually for each of a plurality of divided regions into which said first region is divided;

and a second mode in which image signals are read out from a second photoelectric conversion element group arranged in a second region that is smaller than said first region of said image sensing plane, the readout of said signal images of said divided regions is performed in said first mode between the readout of image signals in said second mode and the subsequent readout of image signals in said second mode,

said method comprising steps of;

calculating correction values based on at least said image signals read out in said first mode, and

performing a white balance process of said image signals read out in said second mode based on said correction values.