DUAL MODE CAMERA SOLUTION APPARATUS, SYSTEM, AND METHOD

• US 20090086074A1
• Filed: 09/27/2007
• Published: 04/02/2009
• Est. Priority Date: 09/27/2007
• Status: Abandoned Application

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Inventors: YANG, Henry Hongli, LI, Hongjun, HE, James Xinping
• Application Number:
  US11/863,093
• Publication Number:
  US 20090086074A1
• Time in Patent Office: Days
• US Class Current: 348/308
• CPC Class Codes: H04N 23/667 Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors

Abstract

A camera solution includes an image sensor and an image processing and control system. At least two different operating modes are supported, with one of the modes having a higher dynamic range. Control of the dynamic range is provided at the system level. The system supports statically or dynamically selecting an operating mode that determines the dynamic range of a camera. In one implementation, the system supports the use of either a conventional image sensor that does not natively support a high dynamic range or a dual-mode image sensor.

Claims

1. A dual-mode camera system in which control of the dynamic range is provided at a system level, comprising:

an image processing and control system, including;

a buffer for image signals received from an image sensor having an array of pixels;

an image processor receiving buffered image signals from the buffer; and

a dynamic range mode controller within the image processing and control system selecting an operating mode of the camera system, the operating modes including a first operating mode and a second operating mode, the first operating mode having a high dynamic range (HDR) and the second operating mode having a normal dynamic range that is not HDR (non-HDR).

2. The camera system of claim 1, wherein the dynamic range mode controller is programmable to statically select the operating mode to be one of the operating modes.

3. The camera system of claim 1, wherein the dynamic range mode controller dynamically selects the operating mode based on environmental conditions.

4. The camera system of claim 1, wherein the image sensor does not natively support HDR and the dynamic range mode controller implements the first operating mode by adjusting the exposure time of sets of at least two successive image signals taken by the image sensor array with different exposure times with the image processor combining at least two image signals having different exposure times to form an individual digital image having the high dynamic range.

5. The camera system of claim 1, wherein the image sensor natively supports HDR and non-HDR operating modes, the dynamic range mode controller directing the image sensor to select between HDR and non-HDR operating modes.

6. The camera system of claim 1, wherein the dynamic range mode controller supports the use of image sensors of different types, the dynamic range mode controller when the image sensor does not natively support HDR implementing the first operating mode by adjusting the exposure time of sets of at least two successive image signals taken by the image sensor array to have different exposure times with the image processor combining at least two image signals having different exposure times to form an individual digital image having the high dynamic range, and the dynamic range mode controller when the image sensor natively supports both operating modes directing the image sensor to select between HDR and non-HDR operating modes.

7. The camera system of claim 1, wherein the dynamic range mode controller dynamically selects the operating mode by detecting environmental conditions and in response to detecting that a normal dynamic range is required selecting the second operating mode in which the image sensor is operated to generate images with a normal dynamic range and the dynamic range mode controller in response to detecting an extended dynamic range is required selecting the first operating mode in which the image sensor is operated to generate a high dynamic range.

8. A dual-mode camera in which control of the dynamic range is provided at a system level, comprising:

an image sensor array having an array of pixels; and

an image processing and control system, including;

an image processor to process image signals received from the image sensor array and generate digital images; and

a dynamic range mode controller in the image processing and control system to select an operating mode of the camera, the operating modes including a first operating mode and a second operating mode, the first operating mode having a high dynamic range (HDR) and the second operating mode having a normal dynamic range that is not HDR (non-HDR).

9. The camera of claim 8, wherein the dynamic range mode controller supports both static and dynamic selection of the operating mode.

10. The camera of claim 8, wherein the operating mode is dynamically selected based on at least one image quality criterion affected by environmental conditions.

11. The camera of claim 8, wherein said image sensor array formed on a first chip, the image processor and the dynamic range mode controller being formed on at least one other chip.

12. The camera of claim 8, wherein the image sensor array has a fixed dynamic range less than the high dynamic range for each individual image signal generated by the image sensor array, the image processor in the first operating mode combining at least two image signals having different exposure times to form an individual digital image having the high dynamic range with the dynamic range mode controller adjusting the exposure time of sets of at least two successive image signals taken by the image sensor array to have different exposure times and a buffer is provided to buffer individual sets of image signals having different exposure times.

13. The camera of claim 12, wherein in the second operating mode each digital image is formed from a single image signal.

14. The camera of claim 8, wherein the image sensor array is a dual-mode image sensor array supporting both the first operating mode and the second operating mode, the dynamic range mode controller selecting the operating mode of the image sensor array.

15. The camera of claim 8, wherein the operating mode is dynamically selected based on image quality criteria that includes a contrast criterion, the dynamic range mode controller dynamically selecting the operating mode based on whether the contrast between bright and dark requires an extended dynamic range.

16. The camera of claim 8, wherein the dynamic range mode controller selects the operating mode based on programmable criteria.

17. A dual-mode camera in which the dynamic range is adapted to changing environmental conditions, comprising:

an image sensor having an array of pixels formed on a first chip;

an image processing and control system, including

a buffer for image signals received from the image sensor;

a processor formed on a second chip, the processor processing buffered image signals from the buffer to generate digital images; and

a dynamic range mode controller within the image processing and control system to select an operating mode based on environmental conditions, the dynamic range mode controller in response to detecting an extended dynamic range is required selecting a first operating mode in which the image sensor is operated to generate a high dynamic range and in response to detecting that a normal dynamic range that is not HDR (non-HDR) is required selecting a second operating mode in which the image sensor is operated to generate images with a non-HDR dynamic range.

18. The camera of claim 17, wherein said dynamic range mode controller has a programmable switching response.

19. The camera of claim 17, wherein the image sensor has a fixed dynamic range for a single image signal and a high dynamic range is achieved for the first operating mode by generating control signals to direct the image sensor to adjust the exposure time of sets of at least two successive image signals taken by the image sensor to have different exposure times, the processor combining data from sets of successive image signals with different exposure times to achieve a high dynamic range.

20. The camera of claim 17, wherein the image sensor is a dual-mode image sensor array supporting both the first operating mode and the second operating mode, the dynamic range mode controller selecting the operating mode of the image sensor.