Determination of exposure time for an image frame

• US 10,440,284 B2
• Filed: 01/31/2018
• Issued: 10/08/2019
• Est. Priority Date: 06/10/2015
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Sen, Sumeet
• Primary Examiner(s): Haliyur, Padma
• Application Number:
  US15/885,791
• Publication Number:
  US 20180160023A1
• Time in Patent Office: 615 Days
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06T 7/215 Motion-based segmentation
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/73 by influencing the exposure time

Abstract

An apparatus for adjusting an exposure time for an image frame is presented. The apparatus comprises at least one processing unit and at least one memory. The at least one memory stores program instructions that, when executed by the at least one processing unit, cause the apparatus to process at least one image frame, select at least one region of interest from the at least one image frame, process at least two consecutive image frames to determine a motion field, segment the motion field into at least one motion cluster, select based on the at least one region of interest and the at least one motion cluster, the most relevant motion cluster, and adjust the exposure time based on motion information of the selected most relevant motion cluster.

Claims

1. An apparatus, comprising:

at least one processing unit;

at least one memory, wherein the at least one memory stores program instructions that, when executed by the at least one processing unit, cause the apparatus to;

process at least one image frame;

select at least one region of interest from the at least one image frame;

process the at least one image frame and a second image frame to determine a motion field;

determine that the region of interest is not in the motion field;

based on determining that the region of interest is not in the motion filed, adjust an exposure time based on the region of interest.

2. An apparatus according to claim 1, wherein the at least one memory stores program instructions that, when executed by the at least one processing unit, cause the apparatus to:

process the at least two consecutive image frames to determine the motion field.

3. An apparatus according to claim 1, wherein the at least one memory stores program instructions that, when executed by the at least one processing unit, cause the apparatus to:

determine at least one salient region from the at least one image frame, the salient region comprising at least a portion of a salient object; and

select the at least one salient region as the at least one region of interest.

4. An apparatus according to claim 1, wherein the at least one memory stores program instructions that, when executed by the at least one processing unit, when selecting the region of interest, cause the apparatus to:

determine at least two salient regions of interest from the at least one image frame; and

select a salient region closest to a center of the at least one image frame and the salient object as the region of interest.

5. An apparatus according to claim 1, wherein the at least one memory stores program instructions that, when executed by the at least one processing unit, when selecting the region of interest, cause the apparatus to:

determine a weight for each region of interest.

6. An apparatus according to claim 5, wherein the weight of a region of interest is based on at least one of the following:

a size of the region of interest; and

a location of the region of interest.

7. An apparatus according to claim 1, wherein the at least one memory stores program instructions that, when executed by the at least one processing unit, cause the apparatus to:

identify at least one face in the at least two image frames, the at least one face being the salient object; and

select at least one region comprising the at least one face as the at least one region of interest.

8. An apparatus according to claim 1, wherein selecting the region of interest is further based on an indication from a user to select the region of interest.

9. An apparatus according to claim 1, wherein the at least one memory stores program instructions that, when executed by the at least one processing unit, cause the apparatus to:

adjust the at least one region of interest based on a size of the salient object.

10. A method comprising:

processing at least one image frame;

selecting at least one region of interest from the at least one image frame;

processing the at least one image frame and a second image frame to determine a motion field;

determining that the region of interest is not in the motion field;

based on determining that the region of interest is not in the motion filed, adjusting an exposure time based on the region of interest.

11. A method according to claim 10, further comprising processing the at least two consecutive image frames to determine the motion field.

12. A method according to claim 10, further comprising:

determining at least one salient region from the at least one image frame, the salient region comprising at least a portion of a salient object; and

selecting the at least one salient region as the at least one region of interest.

13. A method according to claim 10, further comprising:

determining at least two salient regions of interest from the at least one image frame; and

selecting a salient region closest to a center of the at least one image frame and the salient object as the region of interest.

14. A method according to claim 10, further comprising:

identifying at least one face in the at least one image frame; and

selecting at least one region comprising the at least one face as the at least one region of interest.

15. A method according to claim 10, further comprising adjusting the at least one region of interest based on a size of the salient object.

16. One or more computer-readable storage devices having computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

processing at least one image frame;

selecting at least one region of interest from the at least one image frame;

processing the at least one image frame and a second image frame to determine a motion field;

determining that the region of interest is not in the motion field;

based on determining that the region of interest is not in the motion filed, adjusting an exposure time based on the region of interest.

17. The one or more computer-readable storage devices of claim 16, wherein the computer-executable instructions further cause the one or more processors to perform operations comprising processing the at least two consecutive image frames to determine the motion field.

18. The one or more computer-readable storage devices of claim 16, wherein the computer-executable instructions further cause the one or more processors to perform operations comprising:

determining at least one salient region from the at least one image frame, the salient region comprising at least a portion of a salient object; and

selecting the at least one salient region as the at least one region of interest.

19. The one or more computer-readable storage devices of claim 16, wherein the computer-executable instructions further cause the one or more processors to perform operations comprising:

determining at least two salient regions of interest from the at least one image frame; and

selecting a salient region closest to a center of the at least one image frame and the salient object as the region of interest.

20. The one or more computer-readable storage devices of claim 16, wherein the computer-executable instructions further cause the one or more processors to perform operations comprising:

identifying at least one face in the at least one image frame; and

selecting at least one region comprising the at least one face as the at least one region of interest.