SYSTEM AND METHOD FOR CAPTURING DIGITAL IMAGES USING MULTIPLE SHORT EXPOSURES

• US 20160255262A1
• Filed: 03/01/2016
• Published: 09/01/2016
• Est. Priority Date: 01/10/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lee, Ji Soo, Luo, Jiafu
• Granted Patent: US 10,091,434 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 25/531 by controlling rolling shutters in CMOS SSIS
• CPC Class Codes: H04N 25/533 by using differing integration times for different sensor regions
• CPC Class Codes: H04N 25/583 with different integration times
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components

Abstract

Methods, devices, and computer program products for image sensors with overlapped exposure brackets supporting multiple short exposures are described. In one aspect, a method of capturing an image is disclosed. The method includes capturing, on a first subset of pixels on an image sensor, a first image with a first exposure length. The method further includes simultaneously capturing, on a second subset of pixels on an image sensor, a plurality of images with a second exposure length, wherein the second exposure length is shorter than the first exposure length. The method further includes combining the plurality of images with a second exposure length into a second image. Finally, the method includes combining the first image and the second image.

Claims

1. A method of capturing a high dynamic range image, comprising:

capturing, on a first subset of pixels on an image sensor, a first image with a first exposure length;

capturing, on a second subset of pixels on the image sensor, a second image with a second exposure length during the capturing of the first image; and

combining the first image and the second image to form a high dynamic range image.

2. The method of claim 1, wherein the second exposure length is shorter than the first exposure length.

3. The method of claim 1, wherein the first subset of pixels comprises a first plurality of pixel lines of a pixel array and wherein the second subset of pixels comprises a second plurality of pixel lines of the pixel array.

4. The method of claim 3, wherein the first plurality of pixel lines and the second plurality of pixel lines are interlaced with each other.

5. The method of claim 1, further comprising:

capturing, on the second subset of pixels on the image sensor, a third image with the second exposure length during the capturing of the first image; and

combining the first image, the second image, and the third image to form the high dynamic range image.

6. The method of claim 5, wherein the second image and the third image are captured sequentially during the capturing of the first image.

7. The method of claim 1, wherein the first image and the second image each comprise at least one readout frame and one reset frame.

8. An electronic device for capturing a high dynamic range image, comprising:

a CMOS visible image sensor comprising a plurality of pixels including a first subset of pixels and a second subset of pixels; and

a processor coupled to the image sensor and configured to;

capture, on the first subset of pixels of the image sensor, a first image with a first exposure length;

capture, on the second subset of pixels of the image sensor, a second image with a second exposure length during the capturing of the first image; and

combine the first image and the second image to form a high dynamic range image.

9. The electronic device of claim 8, wherein the second exposure length is shorter than the first exposure length.

10. The electronic device of claim 8, wherein the first subset of pixels comprises a first plurality of pixel lines of a pixel array and wherein the second subset of pixels comprises a second plurality of pixel lines of the pixel array.

11. The electronic device of claim 10, wherein the first plurality of pixel lines and the second plurality of pixel lines are interlaced with each other.

12. The electronic device of claim 8, wherein the processor is further configured to:

capture, on the second subset of pixels on the image sensor, a third image with the second exposure length during the capturing of the first image; and

combine the first image, the second image, and the third image to form the high dynamic range image.

13. The electronic device of claim 12, wherein the plurality of images are captured sequentially during the capturing of the first image

14. The electronic device of claim 8, wherein the first image and the second image each comprise at least one readout frame and one reset frame.

15. An apparatus for capturing a high dynamic range image, comprising:

means for capturing, on a first subset of pixels on an image sensor, a first image with a first exposure length;

means for capturing, on a second subset of pixels on the image sensor, a second image with a second exposure length during the capturing of the first image; and

means for combining the first image and the second image to form a high dynamic range image.

16. The apparatus of claim 15, wherein the second exposure length is shorter than the first exposure length.

17. The apparatus of claim 15, wherein the first subset of pixels comprises a first plurality of pixel lines of a pixel array and wherein the second subset of pixels comprises a second plurality of pixel lines of the pixel array.

18. The apparatus of claim 17, wherein the first plurality of pixel lines and the second plurality of pixel lines are interlaced with each other.

19. The apparatus of claim 15, wherein the second image comprises a combined plurality of images with the second exposure length.

20. The apparatus of claim 19, wherein the plurality of images are captured sequentially during the capturing of the first image

21. The apparatus of claim 15, wherein the first image and the second image each comprise at least one readout frame and one reset frame.

22. A non-transitory computer readable storage medium having stored thereon instructions that, when executed, cause a processor of a device to:

capture, on a first subset of pixels on an image sensor, a first image with a first exposure length;

capture, on a second subset of pixels on the image sensor, a second image with a second exposure length during the capturing of the first image; and

combine the first image and the second image to form a high dynamic range image.

23. The non-transitory computer readable storage medium of claim 22, wherein the second exposure length is shorter than the first exposure length.

24. The non-transitory computer readable storage medium of claim 22, wherein the first subset of pixels comprises a first plurality of pixel lines of a pixel array and wherein the second subset of pixels comprises a second plurality of pixel lines of the pixel array.

25. The non-transitory computer readable storage medium of claim 24, wherein the first plurality of pixel lines and the second plurality of pixel lines are interlaced with each other.

26. The non-transitory computer readable storage medium of claim 22, wherein the second image comprises a combined plurality of images with the second exposure length.

27. The non-transitory computer readable storage medium of claim 26, wherein the plurality of images are captured sequentially during the capturing of the first image

28. The non-transitory computer readable storage medium of claim 22, wherein the first image and the second image each comprise at least one readout frame and one reset frame.