Method and apparatus for remote detection of focus hunt

• US 10,194,072 B2
• Filed: 06/08/2015
• Issued: 01/29/2019
• Est. Priority Date: 06/08/2015
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Kleyman, Irina, Bekiares, Tyrone D., Schmidt, Hinrich A.
• Primary Examiner(s): Kalapodas, Dramos
• Application Number:
  US14/733,625
• Publication Number:
  US 20160360090A1
• Time in Patent Office: 1,331 Days
• CPC Class Codes: H04N 1/00204 with a digital computer or a digital computer system, e.g. an internet server programmed control between transmitter and receiver or between image input and image output device H04N1/32561
• CPC Class Codes: H04N 1/00244 with a server, e.g. an internet server fax-servers or the like for store and forward H04N1/324
• CPC Class Codes: H04N 17/002 for television cameras
• CPC Class Codes: H04N 2101/00 Still video cameras
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet
• CPC Class Codes: H04N 23/675 comprising setting of focusing regions
• CPC Class Codes: H04N 5/77 between a recording apparatus and a television camera
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source
• CPC Class Codes: H04N 9/8205 involving the multiplexing of an additional signal and the colour video signal

Abstract

A communication system provides for automated detection, and resolution, of focus hunt. A server determines whether a predetermined number of blur metric transition (BMT) cycles, associated with a video stream, have occurred within a predetermined period of time or number of frames. In response to determining that the predetermined number of BMT cycles have occurred, the server determines that focus hunt has occurred. A BMT occurs when first and second blur metrics, determined for first and second video frames, transition from being greater than a blur metric threshold to being less than the threshold, or vice versa. In turn, a BMT cycle occurs when a BMT, of a first BMT and a second BMT, comprises a transition of blur metrics from less than the threshold to greater than the threshold and the other BMT comprises a transition of blur metrics from greater than the threshold to less than the threshold.

Claims

1. A method for automated detection of focus hunt in association with a video stream, the method comprising:

determining an occurrence of a plurality of blur metric transition cycles in association with the video stream, wherein determining an occurrence of each blur metric transition cycle of the plurality of blur metric transition cycles comprises;

determining a plurality of blur metric transitions, wherein determining each blur metric transition of the plurality of blur metric transitions comprises determining a plurality of blur metrics in association with a plurality of video frames of the video stream, wherein a first blur metric of the plurality of blur metrics is greater than a blur metric threshold and a second blur metric of the plurality of blur metrics is less than the blur metric threshold; and

wherein a blur metric transition cycle occurs wherein a first blur metric transition of the plurality of blur metric transitions comprises a transition from a blur metric that is less than the blur metric threshold to a blur metric that is greater than the blur metric threshold, and a second blur metric transition of the plurality of blur metric transitions comprises a transition from a blur metric that is greater than the blur metric threshold to a blur metric that is less than the blur metric threshold;

determining a number of blur metric transition cycles of the plurality of blur metric transition cycles that occur within a predetermined period of time or within a predetermined number of frames; and

determining that focus hunt has occurred based on the determined number of blur metric transition cycles.

2. The method of claim 1, further comprising:

in response to determining that focus hunt has occurred, generating a notification that focus hunt has been detected.

3. The method of claim 1, further comprising:

in response to determining that focus hunt has occurred, resolving the focus hunt.

4. The method of claim 3, wherein resolving the focus hunt comprises performing one or more of:

conveying an instruction to a video camera that sourced the video stream that manipulates a position of the video camera to achieve a steady focus state;

conveying, an instruction to the video camera to adjust the video camera'"'"'s iris control;

conveying an instruction to the video camera to enable a wide dynamic range feature; and

conveying an instruction to the video camera to disable automatic focus.

5. The method of claim 1, wherein the predetermined period of time is a third predetermined period of time and the predetermined number of frames is a third predetermined number of frames, and wherein determining an occurrence of a blur metric transition cycle comprises determining that the first blur metric transition and the second blur metric transition occur within a second predetermined period of time or a second predetermined number of video frames of each other.

6. The method of claim 5, wherein determining a blur metric transition comprises determining that a first video frame, associated with the first blur metric, and a second video frame, associated with the second blur metric, are within a first predetermined period of time or a first predetermined number of video frames of each other.

7. The method of claim 1, wherein determining a plurality of blur metrics in association with a plurality of video frames comprises determining, for a video frame of the plurality of video frames, a blur metric by filtering out color information associated with the video frame and analyzing black and white information associated with the video frame.

8. The method of claim 1, wherein a blur metric transition comprises a transition of the image from sharp-to-blurry or from blurry-to-sharp over a plurality of video frames and wherein a blur metric transition cycle comprises a transition of the image from sharp-to-blurry-to-sharp or from blurry-to-sharp-to-blurry.

9. A server capable of detecting focus hunt in association with a video stream received from a remote video camera, the server comprising:

a processor; and

an at least one memory device that is configured to store a set of instructions that, when executed by the processor, cause the processor to perform the following functions;

determining an occurrence of a plurality of blur metric transition cycles in association with the video stream, wherein determining an occurrence of each blur metric transition cycle of the plurality of blur metric transition cycles comprises;

determining a plurality of blur metric transitions, wherein determining each blur metric transition of the plurality of blur metric transitions comprises determining a plurality of blur metrics in association with a plurality of video frames of the video stream, wherein a first blur metric of the plurality of blur metrics is greater than a blur metric threshold and a second blur metric of the plurality of blur metrics is less than the blur metric threshold; and

wherein a blur metric transition cycle occurs wherein a first blur metric transition of the plurality of blur metric transitions comprises a transition from a blur metric that is less than the blur metric threshold to a blur metric that is greater than the blur metric threshold, and a second blur metric transition of the plurality of blur metric transitions comprises a transition from a blur metric that is greater than the blur metric threshold to a blur metric that is less than the blur metric threshold;

determining a number of blur metric transition cycles of the plurality of blur metric transition cycles that occur within a predetermined period of time or within a predetermined number of frames; and

determining that focus hunt has occurred based on the determined number of blur metric transition cycles.

10. The server of claim 9, wherein the at least one memory device is configured to store a set of instructions that, when executed by the processor, cause the processor to:

in response to determining that focus hunt has occurred, generating a notification that focus hunt has been detected.

11. The server of claim 9, wherein the predetermined period of time is a third predetermined period of time and the predetermined number of frames is a third predetermined number of frames, and wherein the at least one memory device is configured to store a set of instructions that, when executed by the processor, cause the processor to determine an occurrence of a blur metric transition cycle by determining that the first blur metric transition and the second blur metric transition occur within a second predetermined period of time or a second predetermined number of video frames of each other.

12. The server of claim 11, wherein the at least one memory device is configured to store a set of instructions that, when executed by the processor, cause the processor to determine a blur metric transition by determining that a first video frame, associated with the first blur metric, and a second video frame, associated with the second blur metric, are within a first predetermined period of time or a first predetermined number of video frames of each other.

13. The server of claim 9, wherein the at least one memory device is configured to store a set of instructions that, when executed by the processor, cause the processor to determine a plurality of blur metrics in association with a plurality of video frames by determining, for a video frame of the plurality of video frames, a blur metric by filtering out color information associated with the video frame and analyzing black and white information associated with the video frame.

14. The server of claim 9, wherein the at least one memory device is configured to store a set of instructions that, when executed by the processor, cause the processor to determine a blur metric by determining whether an image present in one or more video frames is blurry or sharp.

15. The server of claim 14, wherein a blur metric transition comprises a transition of the image from sharp-to-blurry or from blurry-to-sharp over a plurality of video frames and wherein a blur metric transition cycle comprises a transition of the image from sharp-to-blurry-to-sharp or from blurry-to-sharp-to-blurry.