Imaging apparatus and imaging method

• US 20060119903A1
• Filed: 11/10/2005
• Published: 06/08/2006
• Est. Priority Date: 11/11/2004
• Status: Active Grant

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Chiba, Takuma, Okamoto, Kazuo, Juri, Tatsuro, Nagaishi, Yuji
• Granted Patent: US 7,876,980 B2
• Time in Patent Office: Days
• US Class Current: 358/474
• 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 25/445 by skipping some contiguous pixels within the read portion of the array
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors

Abstract

The resolution, frame rate, or both can be improved when imaging moving subjects in an imaging apparatus using a CMOS image sensor. The imaging apparatus has an image sensor having a two-dimensional array of pixels. Each of the pixels includes an element operable to produce an electric charge by photoelectrically converting light from an imaged subject and a part operable to accumulate the produced charge and output an accumulated charge or a signal representing the accumulated charge. The imaging apparatus also has an area control unit operable to define a specified area of the image sensor containing a plurality of pixels and an area density control unit operable to specify a density of pixels read from the specified area defined by the area control unit.

Claims

1. An imaging apparatus comprising:

an image sensor having a two-dimensional array of pixels, each of the pixels comprising an element operable to produce an electric charge by photoelectrically converting light from an imaged subject, and a part operable to accumulate the produced charge and output an accumulated charge or a signal representing the accumulated charge;

an area control unit operable to define a specified area of said image sensor containing a plurality of pixels; and

an area density control unit operable to specify a density of pixel signal in the specified area in the image sensor defined by said area control unit, the pixel data being to be output from the image sensor.

2. An imaging apparatus according to claim 1, wherein the density of the pixel to be output from the image sensor is controlled to correspond to the specified value by thinning pixels to be read, when the specified area having a density specified by the area control unit and the area density control unit is read.

3. An imaging apparatus according to claim 1, further comprising:

a pixel mixing unit operable to mix pixel signal, wherein the density of the pixel to be output from the image sensor is controlled to correspond to the specified value by mixing the pixel signal, when the specified area having a density specified by the area control unit and the area density control unit is read.

4. An imaging apparatus according to claim 1, further comprising:

an image processing unit operable to apply a specific signal processing to an output of said image sensor and output an image signal; and

a motion detection unit operable to identify an area containing a moving subject based on the image signal output from said image processing unit;

wherein the area identified by said motion detection unit is the specified area defined by said area control unit.

5. An imaging apparatus according to claim 4, wherein the image processing unit further comprising:

an image forming unit operable to form an image in which density of each pixel of whole areas corresponds to minimum density that means minimum among whole densities specified by the area density control unit,

wherein the image is provided as input video signal to the motion detection unit.

6. An imaging apparatus according to claim 5, wherein the image in which density of each pixel of whole areas corresponds to the minimum density is formed in the image processing unit by thinning the pixels.

7. An imaging apparatus according to claim 5, wherein the image in which density of each pixel of whole areas corresponds to the minimum density is formed in the image processing unit by averaging the pixels adjacent each other.

8. An imaging apparatus according to claim 4, wherein said motion detection unit is operable to identify, as the area containing the moving subject an area containing a plurality of pixels exhibiting a signal change at least equal to a specific threshold value between temporally consecutive frames output from said image processing unit.

9. An imaging apparatus according to claim 4, wherein said area density control unit is operable to set the density of pixels read from the area identified by said motion detection unit to a higher density than a density of pixels read from an area outside the identified area.

10. An imaging apparatus according to claim 4, wherein said area density control unit is operable to set the density of pixels read from the area identified by said motion detection unit to a lower density than a density of pixels read from an area outside the identified area.

11. An imaging apparatus according to claim 1, further comprising:

an image processing unit operable to apply a specific signal processing to an output of said image sensor and output an image signal; and

a frequency component detection unit operable to process a frame contained in the image signal output from said image processing unit and identify an area in the frame containing pixels having a high frequency component;

wherein the area identified by said frequency component detection unit is the area defined by said area control unit.

12. An imaging apparatus according to claim 1, further comprising:

a line control unit operable to specify at least one of horizontal line or vertical line to be read at each frame,

wherein pixel signal of the horizontal line or the vertical line specified by the line control unit are input to the frequency component detection unit.

13. An imaging apparatus according to claim 1, further comprising:

an image processing unit operable to apply a specific signal processing to an output of said image sensor and output an image signal; and

a focus control unit operable to control image focusing in said imaging apparatus;

wherein an area including a rangefinding point used by said focus control unit to control focusing is the area defined by said area control unit.

14. An imaging apparatus according to claim 2, wherein said image processing unit is operable to convert signals in each read area to a specified pixel density so that the pixel density of all signals read from the image area is the same specified pixel density and output the resulting image signal.

17. An imaging apparatus according to claim 1, wherein said image sensor is a CMOS image sensor.

18. An imaging apparatus according to claim 1, further comprising an address control unit operable to control the pixels read from said image sensor.

15. An imaging apparatus comprising:

an image sensor having a two-dimensional array of pixels, each of the pixels comprising an element operable to produce an electric charge by photoelectrically converting light from an imaged subject and a part operable to accumulate the produced charge and output an accumulated charge or a signal representing the accumulated charge; and

an area density control unit operable to segment said image sensor into a plurality of specified areas and specify a density of pixels read from each of the specified areas.

16. An imaging apparatus according to claim 15, further comprising:

an image processing unit operable to apply a specific signal processing to an output of said image sensor and output an image signal;

wherein said image processing unit is operable to convert signals in each read area to a specified pixel density so that the pixel density of all signals read from the image area is the same specified pixel density and output the resulting image signal.

19. An imaging method for capturing images from an image sensor having a two-dimensional array of pixels, said method comprising:

defining a specified area of the image sensor containing a plurality of pixels;

specifying a density of pixels read from the specified area;

reading signals from the specified area at the specified pixel density; and

converting signals from each area to a specified pixel density so that the pixel density of all signals in the image is the same specified pixel density.

20. An imaging method according to claim 19, wherein in said specifying, the density of pixels read from the defined area are set to a higher pixel density than in an area outside the defined area.

21. An imaging method according to claim 19, wherein in said specifying, the density of pixels read from the defined area are set to a lower pixel density than in an area outside the defined area.

22. An imaging method according to claim 19, wherein said image sensor is a CMOS image sensor.